IMC doesn't count towards a JAA IR - it used to count towards a CAA IR, but these, of course, can't be done anymore.
I'm doing an IMC at the moment and it's the hardest bit of flying I've done - normal flying is like trying to juggle with three balls, adding IFR throws another three in on top! Great fun and very satisfying when the foggles come off (or, even better, break cloud) and the runway is bang in front of you.
I would have done an FAA IR if I could have taken a month off but unfortunately no chance. Also if you do any ICAO IR (South Africa, US, Oz, etc) then you can now do only a 15 hour conversion to get a JAA one (plus exams plus flight tests plus.... etc).
BTW, I'm fairly sure you need a class 1 medical for a JAA IR.