Pro Tools has to see some kind of Digidesign hardware (or the m-audio hardware that works with PT) to even open Pro Tools. You can use other devices along side the digidesign/m-audio units but either one of these must also be present to be able to use Pro Tools.
Because we live in a capitalistic society (preditorial) these companies take care of their own and don't share much. But each firewire device will have a list of what programs it handles. Protools is very very protective so it prioritizes itself for certain manufacures. Digidesigns for LE and M-audio for M Powered. I run M powered on a M Aduio 1814. LE and M Powered are pretty much the same program so the real choice is the fire wire unit. Also to note, is that fire wire is a Mac invention so depending an your computer you may want to look into USB 2 wich is a little faster. Good luck
