Audioque HDC 315, what size box should i get? What amp?

Ive been looking into getting a new system for a while now, since i sold my last one with my car. Ive been doing a lot of research, and ive decided on getting an Audioque HDC315. I have a 2001 jeep grand cherokee, so box size isnt an issue. I plan on having it specially made, but i need to know what size the box needs to be, and what it should be tuned to. I have no idea what the tuning even effects, but ive heard that its important, so i figured i should ask about it. I also need to decide on an amp. Ive had my eye on the hifonics hfi1000.1 class d amp. I would be running it at one ohm, which is 1000 watts rms exactly what the subs rated for. The only problem i have with it is that i know nothing of its quality, and dont want a cheap amp that breaks 2 months after i get it. I was also looking at getting the audioque aq750 amplifier, if i got this i would run the sub at 2 ohms. The problem with this amp is that 750 watts rms would be underpowering the sub, and the amp is $200, vs the hifonics at $160. If you could tell me which one of these would be better or reccomend any others i would appreciate it