What to wear, oh, what to wear??

Hi, all, any advice would be much appreciated.

I'm participating in a swim/run this weekend. It will be my first! I'm excited but TOTALLY confused about what to wear.

I have a wetsuit, and I know I should wear some sort of shorts (maybe something without a pad, since there's no bike?) but what about up top? The tri-tops I've seen seem a little... unsupportive. I can't run without a sports bra (not complaining, lol!! ;) ), I normally wear those Nike ones that are cupsize. I was thinking maybe the sportsbra and then pulling a top over after I got out of the wetsuit? Does anyone know of a good (quickdrying) sports bra that might work?