I, too have found that 44R suits and sport coats generally tend to be cut to fit a more athletic individual, while 46R tend to be cut for more portly individuals. I measure to a 47 coat and a 35 to 36 pant, depending on the season (spring / summer I tend to lose some weight as I work more on triathlon training rather than just weightlifting and treadmill, which are my exercises in the winter).
I have been able to go with separates with some success. I have had good luck and bad luck with JAB - sometimes the pants portion of the separates work well, other times they don't. Either way, an off-the-rack 46R or 48R jacket needs major surgery to fit me everywhere other than the chest and shoulders. One of the worst I have is a Burberry sport coat I just took to my tailor, which needs 8-10" taken out of the midsection.
I also just recently ordered my first custom suit, and anxiously await the first fitting in a couple weeks and the delivery of the suit in 6 weeks.
Oh, and to the OP - you shouldn't feel overdressed in a suit - it's comforting for a client to see his advisors (including bankers) take their job seriously enough to dress appropriately.