Honda NOS rings are hard to find these days but they do turn up. David Silver and CMS in Holland are two potential suppliers whenever they turn any up. Check their website regularly.
There are quite a few other options it seems as there’s been much discussion over recent years on various forums.
Recently Ralf Buhl in Germany advised that full barrel piston and Ring sets were available from Germany through Gerhard Mossner from TeamDor http://www.teamdor.com/
Not sure if you can just get the rings and if they are compatible with the standard pistons though.
1100F compression rings are different that the “R” rings. Slightly thicker by 0.2mm which means a bit more friction = slightly less power = last longer. You would have to modify the piston groove to use these.
Wiseco rings are compatible with the original pistons to a point. Both compression rings are identical to the R ones, but the oil control ring is not. I believe Gary Wise has used these in the past. You use the actual scraper rings but use the existing Honda, expander between the rings. The Wiseco expander is quite different and would require modification of the piston to increase the groove to accomodate it. Again I think Andre has done this with some of his engine rebuilds.
The Wiseco part number I believe is 2795XC available in both 70mm & 71mm.
I’m sure Andre and Gary can add to this info.