I finally pulled the trigger as well on the 460 Rowland Conversion kit from 460 Rowland last month, after a long time of research. It's still on backorder, hoping it ships later this month or next month. The suppressor I ordered for it 6 months ago is just waiting on tax stamp (FFL told me it probably will be another 2-3 months wait). But it should be a fun gun. I got their V2 Recoil Damper as well and the extra tuning spring kit, so can get it all set up to run both 460 Rowland ammo and 45 ACP. I bought some of the 460 Rowland 290gr Whisper ammo to try out as well in suppressed. I haven't bought the reloading die or brass yet to start loading my own ammo yet.
Keep us posted on how you like the Clark version.