I bind either with an underworks tritop, or gc2 compression shirts. They're designed with people with gynaecomastia in mind, so I don't know if they're stronger than Underarmour compression shirts, but I can't imagine anything weaker working. I wouldn't want to wear the gc2, or even my tritop, with a tight shirt anyway, because although it looks like pecs with a looser shirt on with anything tighter it's clear that there's no separation between the two pecs due to the shirt stretching over them.
I can't exercise with either of them on to be honest, but then I can't stand wearing them all the time even when I'm not doing anything physical. I wore one to the gym, just on the cross trainer and it wasn't so bad, but later that week I went to circuit training and almost had to bail out it was so hard. I ended up bruising myself or something and spending the next week unable to breathe deeply or do anything else without being in pain.
Compression, of any sort, and exercise is a bad combination.