Thanks for the info.
After more surfing and finding some reviews on both - especially at Musician's Friend web-site - I'm going with the E-MU 0404.
(And to the guy who said I "may be a bit confused". Hey - I *know* I'm confused! And reading the parts of the REW manual I've read just made me even *more* confused -

But I'm going to try to read the entire manual before coming back and asking more questions.)
Thanks again,
Bill