Your KB and mouse should be fine if they're USB. To what extent (ie: anything beyond a right mouse button and a scroll wheel) I don't know.

As for displays, looks like it comes with one ADC and one DVI socket, so you can get at least one of the spare screens working with a DVI->VGA adapter).

Wow, I've never met another rabid Mac proponent in the workplace. When I mention Macs, I receive comments along the line of "They're hopeless. I had to use one in 1988, and their screens are too small". Sigh.