I've trained at Rio JJ for just over a year now; I actually lived a few blocks away as well when I first started training. You should give Pete a call and stop by man, you'll love it!
Don't worry about being a smaller guy at a place like Rio JJ, I'm 5'6" and about 140lbs soaking wet. In the last six months, I've seen a lot more guys, around my size, walk through the doors, you won't have any trouble finding a training partner. But, it's always the giants who I always get more excited to spar with, they do a pretty good job of letting me think that I can actually compete with them. It's a nice little incentive to keep training when you're not worried about getting crushed when you spar.
Good luck picking a place, but trust me when I tell you, you won't look any further after you stop by Rio Jiu Jitsu.