Being new to wearing thongs, I have ordered a number of differing styles from various sources.  To date the JM Skinz Thong is the most comfortable for all day wear.  The waist band is comfortably wide and soft with no pinching, the pouch area can accomodate packages (deflated and inflated) and the tail piece is comfortably wide, not being inclined to giving the wearer a super-wedgie.

The Skinz Thong is reasonably priced and perfectly true to size.

Now if they'd make a low rise bikini with backside gathering like the excellent Go Software suits.