That ought to be a sweet keyboard! With the standard 108-key US ASCII layout, I can't really see any problems with it in Linux.
Are you ordering Mail Order? If so, yeah, it's a crap shoot whether or not they'll take it back, and that bad boy is expensive.
I use a Saitek Eclipse Red SE backlit keyboard - not as nice as the one you're looking at, but very similar layout and have had no problem. (My 'extra' multimedia keys for speaker volume and light intensity even worked out of the box.)
Are you thinking about the Red or Brown Switch edition? Be aware of the differences - Red switches are linear action and give neither tactile nor audible feedback. Brown switches are bifurcated and give both an audible and perceptible click for feedback.
Hope you find out it works. If you do, write it up here!