Congrats on the Emac deal recidivist. You should be able to get the job done with a thumbdrive and you can currently do that with the mac mini.
No optical drive? Hmm externals are cheap too so you shouldn't have a hard time picking one up at around $49 USD, new.
As far as keyboards I use a circa g4-sawtooth keyboard that works just fine with my mini. Just avoid the Apple aluminum keyboard with the built-in usb hub. Hub will work but not the keyboard.
