I'm with all those who suggest a Group 1 rather than a Group 3 instrument rating (though I've yet to make use of it).
One point to consider is that, if you're cash constrained (as I was) when finishing your IFR, you can save a fair bit by doing most of the flying in an IFR single.
I did my multi on a Seminole, then for IFR spent the bulk of the time in a DA40 w/G1000 and ADF+DME (MANY shiny newer glass piston singles don't seem to have ADF+DME, which strike me as being of exteme importance in terms of initial IFR training). I then jumped back into the Seminole for the flights with engine failures, and did the ride in that airplane.
You hardly need the second engine for plodding around a hold or doing and NDB approach! That, and I actually found the Seminole far more pleasant to fly an ILS with after the DA40... The ride was passed, and the money saved let me get up to 250 hrs (wrote the IATRA), and do a taildragger checkout and a bit of aerobatics. Also nice to switch between glass and steam gauges, and different aircraft types.
Incidentally, that taildragger checkout helped me get my first job last summer, flying a Pawnee... and without the Group 1 IFR and IATRA, I wouldn't have gotten my second job, at a northern operator (though that ended miserably, and I never flew there).
Cheers,
Colin