Congrat's on your upcoming wedding.
As far as your problem goes, you're not the only one who's in that boat. It seems like slim and/or fit guys aren't taken into consideration by a lot of off the rack suit makers. I'm taller and I weigh more than you do (6ft, 175lbs), but I have the same problems. I don't know how much experience you have with mtm, but you should take a look at moderntailor.com. As far as online mtm companies go, I like it, and it's within your budget...highly recommend.
I read a few comments, and I saw that OP mentioned Indochino. Their customer service is top notch, but IMO, they do a shxtty job of accommodating customer requests, and they did a terrible job of using my measurements. On the other hand, if the suit's fit is really fxcked up (like mine was), they offer to remake it for you. IMO, ModernTailor is better.
Edited by VinnyMac - 11/12/12 at 4:21pm