Wow, a good camera for a good price, that.
I paid about the same for my SCX 8x10, which I think is a rung below this SC (this one certainly looks newer and better than mine).
I can also vouch for using 210mm (just: normal bellows kind of limits the shifting, it'd be better with a bag) and I've had up to a 600mm Apo-Tessar on it at infinity no problem (It just doesn't reach long enough for my 28"/711mm Anastigmat though).
Definitely a good gateway drug into 8x10...