i have a dcab, but i DO NOT have roof racks. HOWEVER, there's a dcab at work that has Yakima's over the cab. Looks pretty good. I had Yakima's on my old 4runner, and they worked really well. Only hauled snowboards.
I'd recommend checking out Yakima and Thule's websites for fitment and then checking ebay or something and find the cheapest price (Yaks and Thule's can get expensive, fast). Most of these types of racks "clip" onto the roof on the upper door sill / rain-gutter. (You're looking for towers, crossbars and whatever accessories i.e. snowboard racks that you'll need to haul whatever you want to haul. Oh -- and locks. I priced out the towers/crossbars/snowboard racks + locks when I sold my racks... it was $400+ new.)
Like I said earlier, check ebay once you know what you need. Another place to find a really good deal is craigslist.org.
One thing I did notice on my 4runner: the silicone pads on the towers rub into the paint and leave little rough spots. This is due to dirt/dust b/t the pad and roof combined w/ wind/vibration from the truck and road -- no way to avoid it. For that reason, I'm not inclined to run Yakima's on my dcab.
I've thought about having racks bolted to my snugtop, but then again, I can fit a ton of gear in the bed w/out worrying about stuff smacking my passengers in the head. So for now line-x'd bed + snugtop = the best snowboard toting system around.
cheers!
-ryan