Thanks guys for you comments. You corroborate my thinking on the use of two very different sounding kbds.
I am torn btwn the 588 (which really would fill the niche as a 88 key piano, making the setup more versatile) since I have no piano. (not to mention the $400 rebate from Korg right now). Downside is as I already mentioned - really poor saxes and no opportunity to add voices. Downside of the 800 is that it's another 61 key machine and more money. Upside is the expansion potential and the quality voices - some which come close to those on T3.
Forgive me for babbling on - I'm processing as I write. Any wisdom from fellow SZ'ers is valued
Tim