Does 2010 seat fit 08? The part numbers are not the same but I am guessing they are still interchangeable.

Yes.
I bought one from KAS and it came with all brackets on, fits fine on my '09.
For some reason it feels better, maybe Kawa revised the foam for gen II.

Does 2010 seat fit 08? The part numbers are not the same but I am guessing they are still interchangeable.

Different parts numbers because they're colors? AFAIK, they're the same otherwise.

Thanks for the replies!

Yep.