yes you're right you will need a linuxmce core. You have two options
1.) buy a FiireEngine from fiire.com and get everything preconfigured
2.) build your own core, using the DVD and old hardware
If you choose option 2, make sure, that you get the special drivers for the VIA graphic card and place them in the right directory (ask the support team of fiire for the download urls..). Or search in this forum and wiki for "VIA Unichrome", "VIA Openchrome", etc...
I can tell from my experience, that the FiireEngine and FiireStation are working out of the box (at least the FiireEngine and the set-top-box, the 1" made some troubles). But the FiireEngine is overpriced and too loud.
eNoodle
edit: ok, rrambo was faster