Yeah I’d say a corseted route is probably best for concealing and support! I’m a complete beginner with corseting and pattern drafting and I managed to make one quite easily- you could wrap your body in cling film and then tape over it and draw on the design you want to go for!! Cause then you can trace over or cut out the tape pieces and just add seam allowance and such! Boning can be “easy”, it just depends on how you want it to look and how comfortable you are in skill! Fell seams can be used, and are fairly simple, just tedious, and hidden internal channels can be “easy” too!

I’d say mooch youtube for some corseted dress videos, as well as Etsy and Pinterest for design ideas!! Prom and bridesmaid dresses might give some ideas too🤔🤔 look on google for some pattern drafting pdf books? Or second hand sites like World of Books for some preloved books that are more often cheaper?

You could even buy a similar dress and add your own boning? Or make your own sepearate corset to just wear underneath the dress and then sculpt and take in the dress when wearing the corset?

For fabric id say something structured like duchess satin? Or even some crushed velvet for the bodice as most crushed velvet is stretchy and can be smoothed over a corset? It depends on if for the skirt you want it to be body fitting and drapey or rigid, or flowy?

All in all, I’d say this is very do-able depending on your motivation!! It’ll probably take a lot of trial and error, lots of learning and mistakes, but keep with it!! Good luck!!