I'm 5ft, size 6-8 and a similar body shape to you.
Whether you go for a jumpsuit or dress, I'd suggest something with a belted waist so you can cinch in at the right waist position.
I love jumpsuits and have several I've bought over the years, all with belts and cropped or ankle length, but they can be tricky to fit - the length from neckline to crotch needs to fit properly otherwise will look out of proportion.
I've bought smart-ish jumpsuits in the past from petite sections in New Look, Dorothy Perkins and Boden.
I've seen (but not bought) nice jumpsuits on Asos petite and Warehouse (who online have a petite section and whose sizing I've generally found small-ish) - both are worth checking out.
I struggle with midi dresses (just don't personally think they suit my height) though have worn a couple of ankle length dresses (bought from Mango, H&M and Other Stories). They were more of a Summer outfit though and possibly not smart enough for a wedding.
Finally, I've resigned myself to getting things altered - dry cleaners can take up length for a tenner usually. I also know a good seamstress for anything more complicated.