You should consider a cap that has flip up side windows. After having 3
different caps on my trucks, and finally getting one with flip up large side
windows, I wouldn't buy anything else. We keep assorted things in the bed, and
it's nice to be able to get things out of the front of the bed, without
climbing over things. We keep the beach chairs, and umbrella in the front of
the bed, and access to them is easy thru the side windows. Caps with sliding
windows, don't give enough access room, in my opinion.
My .02

Ask at tundrasolutions.com  Several of the folks there have
experience with shells.
Ken

Bryan,

I've been very happy with my A.R.E. cap on my '04 Tundra Access cab.
They do make one for the double cab, as well.

The other poster's suggestion about side opening windows is a great
idea; never thought of that !  Instead, I have to crawl up to get stuff
in the front of the bed.  I did put in a Bed Rug, though, so stuff
doesn't slide too much <g> !

Checking ARE's web site, they do offer a model with an option of
side-opening windows.  I have the Z series, but the Impulse can be
ordered with the side windows.  You can check them out at www.4are.com.

HTH !

Dean...