Bella,
IF you can get an off the rack suit that fits nothing beats walking out with it as a done deal. Bare has a very broad line as mentioned, I believe Harveys also has extended sizing but it looks like neither will accommodate you. No need to fret.
A custom suit is the way to go. One measured and built to fit you like it should will cost about the same as a premium off the rack item so cost is not an issue here. Getting it to fit right is the next trick. We have had considerable experience with custom suits and while they are a wonderful solution it's not always a perfect fit first time around. Being near Florida you have several options more available than to many of us.
In order of preference:
1. Go to the maker and be measured and fit. Lets face it, many who want such a suit are not proportioned by the book and 32 measurements just doesn't always capture it all.
2. Find a maker with local representation by a dive shop that will do the measurements and manage any adjustments. How the measurements are taken are critical to fit. Having them done by someone that understands how the maker will translate them helps a lot.
3. Do your own measurements at home and order the suit. This can be done but be very clear about how they want things measured. A wetsuit should be sized to fit with a hint of compression over most of your body. You need to understand who is adjusting the measurements to make the suit just a tad smaller than you.
A hyper stretch suit can be a good solution for a marginal fit but to suggest exploiting it to anything close to 250% is a bad idea. As a suit stretches it gets thinner and hence less protective. It is also under much greater stress and will not last.
Custom tailoring or modifying a wetsuit can be done but materials are hard to find and on a large scale making it look right without the right equipment will be hard. I suggest not going there, at least on the first go round. Start with something simple like adjusting the fit of a hood.
We have had good luck with
Atlan and
Liquidfit. I do give Atlan an edge on cold water suits. Exploring their sites will give you some idea of the measuring process. There are custom houses in Florida that I would urge you to explore making a personal visit to.
Getting this right is vital to you comfort, safety and pleasure as a diver so don't sell yourself short. Do whatever it takes to get it right.
Pete