yeah, 6x9's are great if you arnt running subs.
Ive also seen some nice boxes made to fit into the rear corners of zeds.
Decided to go for a custom box to mount both amps, crossovers and rear 6's in mine. leaves very little room for the soccer kit but wot can you do?
Just a tip tho, if you're looking at front splits, I highly recomend the JVC ones ive got. Ive also got a few mates with them as well, and they really do pump clearly at high vol.