North Dakota
Don't know if you have a Farmtrac dealer near by but if so you may want to look at their product as well. This summer I bought a 48" Farmtrac for my JD455 Diesel L&G tractor (and yes its Cat 1 and 540 rpm). The 455 is 18 PTO hp and handles the 48" fine so I'd think your tractor would have no trouble with a 60".
It seems like a real quality unit and I paid $1500 for it. I think a 60" was around $150 more. These are all gear drive, 6 tines per flange (some brands only have 4), and have a slip clutch. The salesman also sells Woods and thinks the Farmtrac are a much better deal for the money.
Thanks to the ice-age glaciers, here in western NY state we have loam, sand, clay and all of it has lots of rocks. This area is famous for all the 1800's era cobblestone farm houses. I've seen cobbles the size of grapefruits shoot 30 feet out the back of my tiller. I've also hit concrete blocks, bricks, and metal parts. This is just tilling in suburban back yards. I can't imagine a reverse rotation tiller working well in these conditions. If you have fine, stone free topsoil they probably work excellent. But, in my case, I'd rather have all that stuff flying the other way.
Let us know what you end up getting.