well you asked for ideas...how do you feel about some that are slightly off the wall, perhaps even crazy? don't know how much of a diy person you are BUT having a bench and the truck being stick, along with trying to keep things accessible make me lean towards dash mount, IF do-able, it does look like a pretty wide radio compared to my 257
option 1 would be to pull the center vents, make up a custom face plate and mount it there (would also mean removing and capping the "ducting")
option 2 would mean relocating the fan and temp switches which shouldn't be too bad, just extend the wiring and placing elsewhere
option 3, below the factory radio...unless i'm mistaken all i see there is a cd holding slot? 4, not sure what is located below that tho, 12v sockets perhaps? again an easy relocation....and a quick fiberglass build would make it look factory
just tossing it out there....my dodge had a big center-console between the seats so that was out of the question, leg room is minimal...all i was left with was dash. i quite possibly could have fit a full sized rig in there as my 257 has the HP attached and i have well over an inch left on each side