Well, I would say that an IMC for anyone who wants to go on and get an IR is a waste of money. Better to do a FAA PPL and IR, followed by a UK PPL for which the FAA IR will automatically give you an IMC rating for your UK PPL (confused? read on).
Night rating is probably necessary because you need so many hours night P1, night dual and night cross country in order to get the FAA IR under part 141 (but not under part 61).
If you don't understand what he was telling you, why don't you email him back asking him exactly what training he would recommend for you in your situation.
FWIW, if I had my time again here's what I'd do (in this order):
FAA PPL (which gives you night training anyway)
Hours building
ATPL grounschool
More hours building
FAA ME rating
FAA MEIR
JAA CPL in a ME aircraft
JAA IR