This is kind of an old thread but I know something that could work because I just had the same problem and just finished my little project.

So I have my truck. A single cab with a 3 seater bench seat in it and no place to put my $1000 stereo that was in the 300zx.

I took out the bench seat and took 2 bucket seats out of a 2004 Nissan Xterra at a junkyard. Took out the stock seat from the truck. Took a couple bolts out and grinded a little and removed the stock frame from the seat (I left the stock slider on the seat. So then I did the same thing to the Xterra seats except this tim left the sliders on the seat. Drilled a couple holes and bolted a little and was left with the 2 Xterra bucket seats on the stock seat frame that were reclinable and slidable, as well as being able to adjust the stiffness in the seat. You could also control the height and tilt of the seat, and they are waterproof. All this is manuel with no electronic switch's so there was no rewiring. But doing this left me a big gap in between the two seats.

I took my old dual ported box for my 10's and chopped it up a nice bit creating a new box. Instead of having two places for subs on the top as well as being ported through the top. One sub is now at an angle and faces towards my windsheild and there is now a pliglass covered arm rest where the other sub was. The other sub is now located on the front of the box facing the bottom of the dash. The amp is behind the seat and another amp is behind the driver seat to run door speakers. It isnt too hard to sccomplish just takes little while. Total cost for me was just a few days of my time because i got the seats for free.

I can post pictures if you are stilkl interested in putting a system in your truck.

And BTW I wrtapped the top of my box (the arm rest place) with a $2.00 mossy oak throw away seat cover then put a peice of plexiglass on top of it and went around that with a few peices of small angle iron. So it looks pretty custom and nice as well...well nice for living around a bunch of rednecks lol.