From a pure torque perspective, the 645 and 5645 should fit the bill at 133 oz. and 168 oz. respectively. If the 5645 is programmable, it might even allow me to get rid of the servo matchers.

I should definitely try them at some point in a large scale application.

I have both the 5625 and 5645 running in a small size CMP Giles (Saito 56) and my general impression so far was that they were noisy and rather coarse. That is, their movement was not as smooth as similar JRs. I am not talking about the fact they are larger in size and slightly heavier than the JRs.

I got most of my JRs from eBay deals at very attractive prices. They have zero slop at the moment and I have spare gears for them in case they develop some and need attention. despite the high list price, one can occasionally find an 8611A for less than $80 and 8411 or 8311 for less than $60, which makes it a great deal, even compared with the Hitecs.