OP, depends on your working hours, early start time you would fly in from Kill to Newlands X. My parents live there so I know it very well and it's vastly improved and some lovely new developments there. The school situation is something you need to take into account, it's totally full and Ardclough, Naas or Rathcoole are your options which would be a right pain really!. My Dad leaves at 7am to be in Inchicore for 8am everyday and makes it unless something happens!. The traffic is mental but if you have an early start and finish you should be okay but rush hour in the mornings and evenings is a joke!.
Have you thought of Kilcullen even??. Aparantly it's a nice place to live in now and the prices are very good out there. Personally I dislike Naas, but that's just my opinion. Sallins...just a continuation of Naas imho. Kildare town, haven't been in it for years but was never mad about it. Rathangan is nice but it's a good bit out!.
Lived outside Kilcullen most of my life and hated it, have to say Kildare Town much better