Ok,So by that token (more drives the better), I should have raid 5 (or whichever will work) with all 6 drives in it ?
Raid 5 is usually advised against, as in many scenarios it won't perform very well. For example, see: http://www.revsys.com/writings/postgresql-performance.html
If you can't see the forest for the trees,
Cut the trees and you'll see there is no forest.
