There's a fast black patch for the 700, I imagine there's one for the 700i as well. If you're doing long runs of black only clicks make sure you load it - it protects the colour drums, lifts them outta the way so that there's no wear on them.
As for the volume, if you're printing on decent stock, and you look after the machine (cleaned regularly, nip problems in the bud instead of letting them develop into major issues and so on) then I reckon it'd be able to handle that volume ok. If it's low coverage and not graphics intensive work though, the machine'll churn its way through it no problem. That said, if you were doing that type of work there's probably more cost effective options out there...
I'm talking from experience of running a 700 though, not a 700i, they look pretty similar though.