You want 10's in a rollbar enclosure....!!!???? /forums/images/graemlins/eek.gif
I think that's going to be weird....it'll take a LOT of space to do it, and my guess is that you'll be banging your head on it all the time. I'd suggest putting subs somewhere else (like in the sidepanels) and leaving the rollbar mount for the smaller speakers.
That will also solve the next issue of isolating the speakers....YES, if you put subs in the same enclosure with mids and tweeters, you will want to make sure they are "sealed back" drivers or build them into an isolated compartment in the box. The pressure of the subwoofer, will actually "push" the other speakers and cause them to produce sounds that are not supposed to be there.
A "mids & tweeters" rollbar system will be a lot smaller too...so you are less likely to find it in the way, and maybe you won't bash your head on it as much! /forums/images/graemlins/grin.gif