if I hda to go with either, it would be the first one, the reason why I dont like #2 is the band across the butt, also it doesnt follow through to front.
Considering I have ordered zentai suits before (from ebay) I know they can have lots of trouble with ordering. I personally woulndt go to a standalone site to order (especially if taking direct CC and not paypal), also, they are notorious for either not working to solve a problem or still sending wrong item or wanting more money for exchanges for their mistake.
That said, I would order from ebay because;
1.privacy for cc info from payment
2.you have a means to get them to comply or risk negative feedback.
The zentai sellers are basically a handful of shops with tons of separate selling IDs.