first gen tacoma sub in storage cubby

ive seen the threads on TTORA and a few other Tacoma sites about putting an 8" in the rear cubby area of an extended cab first gen. I am redoing my stereo so that it takes of no space and figure this would be the best use of space.

has anyone done this and have good results with a certain sub? the amp i will running is a 200w @4ohm and 300w @2ohm.

I plan to build an actual enclosure and not run it in a free air configuration, so the speaker should be a shallow mount or just not require a lot of air space, from what ive read theres about .25ft^3 of airspace when using MDF to build the box, if i fiberglass the bottom im sure i can squeeze out just a bit more by being more form fitting to the floor of the truck.

suggestions? or would it be possible to put some Kicker 6 3/4" subs in the rear speaker location and build a box that fits behind the pannel?