If I can get/make a one piece, I much prefer them. Currently the measurements are 36/29-39/39-40. I have a narrow rib-cage and a leeettle more tummy than I like! The style I really want is the Lands' End Tugless Tank in modest cut legs & seat, with some extra in the bust!
I had a swimsuit made for me once. It was superb when on, but I really needed a zip up the back for ease of access! Boy, was it hard to tug over my hips, as it had a high back. It took six fittings to get it right, and that was with a professional swimsuit making company, so you can see why I'm a tad reluctant to make one myself!
If I *am* going to go to the bother of making my own, it's GOT to be exactly what I want - no compromises!
I have a swimsuit fabric panel somewhere in the loft that I'm happy to sacrifice to experiments: it was a free gift one time from Croft Mill! Unfortunately, while part of it is nice plain navy blue, the other half is an unpleasant mustardy greenish yellow! IKK!