Hi, I share your liking of white skimpy swimwear. A number of years ago I bought a bespoke very brief white bikini from Dore. It is about 1cm wide at sides with 3/4 back and I have worn it a few times on beaches abroad. It's double lined of soft Lycra fabric but still quite transparent. The first time I wore it my wife said it was transparent when wet and when we went to use nearby toilet facilities, I had just been in the sea and the lady toilet attendant certainly looked long enough at me. Quite erotica actually. So try the following site.
http://www.beachndance.com/Default.asp
Another white bikini I have I bought from waveline on eBay and it came from Singapore I think. It's about 3/4 inch wide with a white liner which still leaves it transparent. Have worn it a couple of times also. Once when visiting an old aunt abroad and she didn't seem to mind it being so.