Putting new "stock" size pistons and rings in an engine that's worn out the originals is a waste of money and time, the bores will have worn as well and the new ones will never seal properly.
Oversize OEM pistons/rings are for exactly this purpose. The bores must be enlarged to use oversize pistons. The sets are in "steps", with Honda the steps are 0.25mm : 0.25mm oversize is step one - S1 and they supply 4 steps so in theory you could rebore the engine 4 times before needing new cylinder barrels (assuming there were no gouges deeper than 0.125mm of course). The performance increase from this tiny overbore is insignificant.
You have found S3 and S4 oversize kits. It seems S1 and S2 are not available. If you ever plan on reboring it again with OEM pistons use the S3 sets and hope S4 is still available if you ever need them. Otherwise it won't matter.
Find an engine machine shop that has experience with and equipment for small bore four cylinder engines! Most bike engine shops in the USA work with V-twin stuff and the tooling is not useful for a Honda four. You don't want some guy learning on your bores! They should want to have your new pistons to fit, I would not trust someone who will try to work to a chart as posted. Make sure the ring gaps are correct if you have a shop do them - if the rings are installed when you get the block and pistons back take them out again and check the gaps, I've had this "favour" of installing the rings happen on a job just to make it hard to check so I wouldn't notice a hacked up gapping. I now hang on to the rings so I can gap them myself, but I learned that the hard way and had to learn how to do the ring gapping properly myself.
