Very pretty - would look fab with wedge sandals! Not sure about undies, depends on the size of your boobs!! If you can wear them, I think a strapless would work well as long as the back strap doesn't show. Or maybe you don't have hanging boobs like me, so could wear no bra at all?!?
Definitely smooth-line pants - personally I like seamless shorts but then I hate thongs - feel like I'm being sliced in half!!