I've bought custom suits from Ron at Buffedbod several times. I have 3 1" bikinis with contour front, 2 of the "hoist" thongs, which are amazing, and 3 thongs. The design is superb on all of them, the construction mostly top-notch. I did have one unravel some seams, but no others. I have probably 8. He's finally charging what his work is really worth, but that makes it harder for me to buy. But he's a great guy, and a one-man army.
I've bought custom from SWIC too, Valeri is a sweet lady. I really like her communications. Unfortunately I haven't hit the optimum design and fabric with her yet. She was very co-operative in re-making a suit that didn't really fit right. The quality was good, the design was not quite the perfect contour that Ron does. I don't find that I wear them as much. Her material and color selection isn't my favorite right now, but it does change, and that's a problem with every custom shop.
Also ordered from Suzi Fox, Liquid Vinyl Clothing. I tried to do a custom special, something she doesn't normally do, and it was just OK. She makes a sliding pouch g-string, I asked her to make it non-sliding. It came out really tiny in the pouch but with a long back strap, which I shortened myself. And even though it's a swim g-string, for me it's bedroom only as things sort of hang out. I think her normal patterns would probably be just fine. I don't like her material selection right now either, but again, that's a moving target.
I got a purple classic from Jupiter at Muscleskins. His work is fine, but the design doesn't work for me. It's just a classic bikini, but it's an odd fit. It also to a long time, but custom work often does. I wouldn't count that as a negative. And Jupiter is a good guy too. Might have to give him another try at some point.
I'd like to give most of these another try, and I'd really like to give kriszsartoria.com a try (she's in Hungary, sells on Etsy).
Lastly I did have a custom one-piece made for my wife with a custom fabric. I had
www.mirasolswimwear.com do it. Not cheap! But good work.
Hope that helps.