No buoyancy allowed anymore. Must be a textile fabric suit. The textiles being used are generally compression textiles, so you will see a slight compression benefit. Some suits have bonded seams, some have flat-lock stitched seams. Some use a locking zipper and some use a lanyard. Paneling will also differ from suit to suit.
Trying these suits on is important just like a wetsuit. If you can try it on with your kit on, even better. The suit sizing could change with your kit on.
What are the key features in the B70 suit that you are finding to be the most attractive curiously?