I took apart the center of my dash today.
Since I don't have any components as of yet, I'm merely taking measurements & seeing what sort of space I have to work with.

Note that the mounts for the double DIN are pretty deeply recessed. The back is plastic ducting for climate control. Don't want to mess with that at all. But I think if I mount the Shuttle box I was thinking of with bottom against that duct, it would work well.

The Shuttle case is 8 inches wide. Considering the metal bracket on the right angles in, It would be a tight squeeze... Considering the amount of fabrication I'm doing to the case itself, I think it will fit.
The cables are going to exit downward, I think. Hell, it may end up being just a motherboard mounted back there! That might not be so bad, as it would help prevent cooling issues.
The other option is to mount the MB somehow where the ashtray & cigarette lighter are now. Again, going without a case, but just a a mounting tray and the motherboard. No, it would stick out too far.
The actual shutle case is 8 inches wide, so I think my plan is doing OK so far with mounting the motherboard against the back.

That box with all the yellow wires (airbag-related?) puts a crimp on the space near the floorboard. That actually sucks, but I think there's still enough room to work with the plan of mounting it against the back of hat cavity. Looking at that back, it may be a cover for wiring. If so, that could be utilised as a mounting plate for the motherboard, as well.
I've put the dash back together, so I'll have to look at that later.

Here's my thoughts as of right this moment:
- 7" dash-mounted LCD from DigitalWW in the top DIN slot
- slim slot-load DVD/CDRW combo between the vents and the climate controls (yes there is room!)
- The Matrix Orbital LCD taking up the lower DIN slot
- Power/HDD lights + a pair of USB 2.0 & possibly a FW port on the lower portion of the console next to the extra 12v power outlets
For the most part, it'll look damn close to stock. That's the goal anyway...
Also, for budgetary reasons, I'm going to get new speakers and one amp. No sub
yet. Also, no overhead video
yet. The way I'm putting it together, It should be relatively easy to add those on later. When I add the sub and seocnd amp, also add a cap. I intend on putting in a fuse block for
everything from the beginning, so that won't be an issue later on.
One thing that I'm thinking about is the GPS placement. One option is on the dash. But the roof would block signal from some angles, possibly Another option is on the roof by the third brakelight. Possibly on the bed, right behind the cab? That's a tough one, as there's no really good mounting options on a pickup.
Actually, I'm thinking that since I'm going to eventually put in overhead video, which means mucking with the headliner, putting the GPS receiver on the roof near the front of the cab. Drill a small hole for the cable and make sure it's weatherproof... I've got time to think about this one.