As Carey said RS 1400 (55 inch) was made for YM2000. It says so on its setup decal. So your 2210 is well matched to it. (Same displacement and nearly identical engine, the increased rated hp may be just an ability to run at higher rpm).
A US tiller has more aggressive tines so I suspect it loads the tractor harder. Still, if you found a nice 5 ft tiller locally for $650 that's the way I would go. It will be built to conventional 3-point dimensions so it doesn't need that special top link. The purpose for that device is to make the top of a RS tiller rotate away from hitting the tires as you lift it but this shouldn't be an issue with a 'standard' tiller.
I'm turning a RS1400 with my YM186D, 18 engine hp. (and 15 pto hp which is why its Japanese twin is named YM1510D). (
photo). It's all the tiller that little tractor wants but this illustrates that your 2210 at near 50% more hp should run a 60 inch tiller fine.
RS1400 is a nice tiller but if you can't find one locally then that $650 tiller is an equally good choice.
Also Winston mentioned changing the fluid upon buying a used tiller. Particularly for the Japanese ones, they were run underwater for their first lifetime. The decent importer where I got mine insisted there was no need to replace fluid but I did anyway. It was milky, ie homogenized water/oil. Subsequent years I have opened the bottom drain before attaching it that season and have always gotten some water out. I don't know if this is residual water from 20 years ago or recent condensation. I suggest make this annual check for water.
And - if you do find a used Yanmar tiller be sure to replace the offside (non-geared side) bearing at the end of the tine axle. A dealer here said he saw import tillers destroyed by neglecting that bearing. He advised replacing it with the same spec sealed bearing.