To minimize the amount of manual editing of my input files I've started to modify the menus in ECCE. One thing that was missing before was the option of selecting a solvation model for Gaussian jobs. I've added that now.
I will eventually submit my changes upstreams, but for now I'll just post a clunky list of changes that I've made:
There are two files to edit:
apps/scripts/codereg/ged03theory.py.
Add the following right after the DFT options section and before the MP options section (
ca line number 273 in my case) 
#Theory options solvation -CAO
            sovSizer = EcceBoxSizer(self,
                                    label = "Solvation",
                                    cols = 2)
            sovLeftSizer = EcceVBoxSizer()
            sovRightSizer = EcceVBoxSizer()
           #Use solvation
            self.useSCRF = EcceCheckBox(self, #useCosmo
                                         label = " Use SCRF"
                                         name = "ES.Theory.SCF.UseSCRF",
                                         default = False)
            sovLeftSizer.AddWidget(self.useSCRF,
                                   border = EcceGlobals.BorderDefault)
           #SCRF type
            scrfChoice = ["PCM",
                             "CPCM",
                             "IPCM",
                             "SCIPCM",
                             "SMD",
                             "Dipole"]
            self.scrf = EcceComboBox(self,
                                        choices = scrfChoice,
                                        name = "ES.Theory.SCF.SCRF",
                                        label = "SCRF type:",
                                        default = 0)
            sovRightSizer.AddWidget(self.scrf,
                                    border = EcceGlobals.BorderDefault)
           #Solvent type
            solventChoice = ["Water",
                             "Acetonitrile",
                             "Methanol",
                             "Ethanol",
                             "Manual",
                             "Benzene",
                             "Chloroform",
                             "Diethylether",
                             "Dichloromethane",
                             "Dichloroethane",
                             "Carbontetrachloride",
                             "Toluene",
                             "Chlorobenzene",
                             "Nitromethane",
                             "Heptane",
                             "Aniline",
                             "Acetone",
                             "Tetrahydrofuran",
                             "Dimethylsulfoxide",
                             "Argon",
                             "Krypton",
                             "Xenon",
                             "n-Octanol",
                             "1-Butanol"
                             "Cyclohexane",
                             "Isoquinoline",
                             "Quinoline",
                             ]   
            self.solvent = EcceComboBox(self,
                                        choices = solventChoice,
                                        name = "ES.Theory.SCF.Solvent",
                                        label = "Solvent:",
                                        default = 0)
            sovRightSizer.AddWidget(self.solvent,
                                    border = EcceGlobals.BorderDefault)
            self.scrfDielec = EcceFloatInput(self,
                                              default = 78.4,
                                              name = "ES.Theory.SCF.Dielectric",
                                              label = "Dielectric Constant:",
                                              hardRange = "(0..)",
                                              unit = "Debye")
            sovRightSizer.AddWidget(self.scrfDielec,
                                    border = EcceGlobals.BorderDefault)
            sovSizer.AddWidget(sovLeftSizer,
                               flag = wx.ALL)
            sovSizer.AddWidget(sovRightSizer,
                               flag = wx.ALL)
            self.panelSizer.Add(sovSizer)
#End theory options solvation -CAO
Also add the following to the 
def CheckDependency(self) block, right before the "
if (EcceGlobals.Category == "MP" or" line:
#       SCRF solvation -- CAO 
        if EcceGlobals.Category == "DFT" or EcceGlobals.Category == "SCF":   
            self.solvent.Enable(self.useSCRF.GetValue())
            self.scrf.Enable(self.useSCRF.GetValue())
            self.scrfDielec.Enable(self.useSCRF.GetValue() and 
                                    self.solvent.GetValue() == "Manual")
#       end SCRF
Edit 
apps/scripts/parsers/ai.gauss03 and put the following somewhere in the file. 
##############################################################################
#
#  Description:
#      SCRF options field -CAO
#       
############################################################################## 
sub SCRFOptions {
  my($options,$result);
  $result = "";
  $options = "";
#scrf type
if ($AbiDict{"ES.Theory.SCF.UseSCRF"}) {
 if ($AbiDict{"ES.Theory.SCF.SCRF"} eq "" ) {
  $options .= "PCM,";
  }
 else {$options .= ($AbiDict{"ES.Theory.SCF.SCRF"}).","};
  
# solvent/dielectric 
 if ($AbiDict{"ES.Theory.SCF.Solvent"} eq "Manual") {
     if (defined($AbiDict{"ES.Theory.SCF.Dielectric"})) {
       $options .= "Dielectric=".$AbiDict{"ES.Theory.SCF.Dielectric"}."";
      } }
      elsif ($AbiDict{"ES.Theory.SCF.Solvent"} eq "") {
    $options .= "Solvent=water"; }
      else { $options .= "Solvent=".$AbiDict{"ES.Theory.SCF.Solvent"};
   }
  if ($options ne "") {
    $result =  "SCRF=(";
    $result .= $options;
    $result .= ") ";
  }
  return  $result;
}
}
Also add the following right below the "
$route .= &SCFOptions;" line:
$route .= &SCRFOptions;
And you're done: