My advice would hinge on how close to the floor your hydroponic system has to be. I can't tell from the picture whether that is sitting down on the floor or up a little ways. If it's off the floor so you can put a reservoir lower than the bottom of the cab you can use pretty much any system you like.
But if it's sitting down on the floor there's some systems you can't use without making things pretty complicated. Hydroponic systems generally depend on the ability to pump solution from a reservoir to a higher point and allowing gravity to recollect the solution into the reservoir. If you don't have gravity to do the work for you, you need to move it with a pump and trust me, that's just a huge can of worms. It's one thing to pump from a large reserve of water but it's a different problem altogether to pump all the solution out of somewhere as it comes in.
So if you've got the room underneath to house the reservoir (or off to the side, lower than the bottom of your cab) I'd suggest a simple Ebb & Flow as probably the easiest way to maximize your vertical space. Otherwise what Propa Gator said would be best (a low-profile DWC). If you're still on the fence about what to fill your hydroponic system with I'll suggest Advanced Nutrients.
But if it's sitting down on the floor there's some systems you can't use without making things pretty complicated. Hydroponic systems generally depend on the ability to pump solution from a reservoir to a higher point and allowing gravity to recollect the solution into the reservoir. If you don't have gravity to do the work for you, you need to move it with a pump and trust me, that's just a huge can of worms. It's one thing to pump from a large reserve of water but it's a different problem altogether to pump all the solution out of somewhere as it comes in.
So if you've got the room underneath to house the reservoir (or off to the side, lower than the bottom of your cab) I'd suggest a simple Ebb & Flow as probably the easiest way to maximize your vertical space. Otherwise what Propa Gator said would be best (a low-profile DWC). If you're still on the fence about what to fill your hydroponic system with I'll suggest Advanced Nutrients.
