IO540
I think the OP also said a weekend.
No neither of those - it will come to me shortly - just to the south west of C de G - by far the best airport for Paris IMHO.
You can walk to the train station if you are feeling keen or a very short taxi and direct into G la N - it is a very regualr service as well. ED was a taxi ride but it is only about 20 minutes.
Pointoise and Toussus are a waste fo time for Paris.