Hi Steve,,If I remember correctly,your truck is now 12v?
How abt. a low end am-fm,casette or c-d player mounted in the glove box and a couple speakers behind the seat,and maybe a couple smaller ones in the dash where the stock speaker would go?
Ive seen it done numerous times,,always worked out well.
Or.........mount something under the dash with a removable face plate.
Use your Imagineering..........youll come up w/something.
Happy Truckin,