I like that tri top, KSH! I may have to get one of those!!!
I, too, always have to wear a bra under my tri top (which has support already). My girls don't need to travel any further south. I got a pretty inexpensive (though good quality) Danskin dry fit type one at Walmart and trained and raced in that for my IM. It was not only really supportive, but didn't chafe and dried fairly quickly. As many sports bras as I have and go through, I've had to "downgrade" my tastes from the $30-$40 kind to the $15-$20 kind I can get at Walmart or Target.