Support underwear - help??

[emmaliz]

I am wearing a very clingy long dress in a couple of weeks to a party and was hoping someone may be able to recommend some appropriate support underwear? Ideally I would like something which holds in my bum and thighs but also comes up high to meet my bra or maybe even includes a bra. The dress is strapless.
I have been looking online but there is so much out there I am struggling. Thanks

For brands I know maidenform are good

Primark and m&s dopants with legs that come upto your boobs. I found primark just as good as anywhere else.

Spanx higher power -come right up to my bra. Combine with wonder bra ultimate strapless

Thank you so much.