As long as you aren't attempting to play games, you shouldn't experience any issues using two monitors. FL Studio, if anything, is more processor intensive then anything (if at all)
One thing to check is that the VGA port supports 1080p, since some cheap motherboards have weird port specifications like that. Also make sure the motherboard supports using both ports at once. Its uncommon that it wouldn't, but if its a cheaper end motherboard you should check.