What are you interested in recording? The Firepod is the general purpose input and output interface between the mics/guitars/other external audio sources and the computer. The eureka seems to be for a specific situation where you'd want to have hardware compression and EQ on one of your audio sources (like vocals). You could plug the Eureka into one of the inputs on the Firepod.

Ahh ok thanks!!!

Just wasn't clear to me thats all ;)