S-10 extended cab, Type of Enclosure?

Thanks for all the ideas guys! I was talking to an expert on stereos today and he gave me some pretty good advice for this box enclosure. He basically said to go with whatever Orion recommends for the correct volume and port size. Not sure about the port size (I can look it up), but the volume is .75 for a vented enclosure with 1500watts. He said Orion doesn't just throw out numbers and that they know what they are talking about so if thats what they recommend for that sub then I guess that's what I should go with...

By the way, this truck is getting a complete overhaul on its sound system. Quite a project! First I have to construct a complete wood setup for the entire back wall and floor. I'm mounting the box to the floor right in the middle behind the center arm rest. All three of the amplifiers that I'm putting in are Orion along with the 10" Orion H2 dual 2 ohm subwoofer. The 1200 mono d amp is getting hooked up to the sub. A 300watt 2-channel is getting hooked up to some Infinity Kappa 63.7i speakers for the doors. The third amp is a 200watt 2-channel running the Infinity Kappa 462.7's in the dash. Plus one Optima yellow top mounted in the back with the rest of the stuff! An insane amount of stuff going into such a little truck! Once I'm finished I'll have to post some pictures. Can't wait until it's done!