Time for a new system...Need help!.....Boston G5's or Hifonics Hfi's

Ok here it is i just got a 86' olds cutlass that im working on and i have a few diff setups and im just tryin to find out what subs to use.

I have a bigger alt (not sure what amp) RV batt under the hood. the big 3 done all 0awg wiring and a 800HC batt in the trunk. Pioneer 5900IB deck, The amp im using is a PowerBass ASA 1500.1D.

Ok now for the Question im really asking. What subs to use?

Two 12" Boston G5's in a small sealed box at 1 ohm.

OR

Four 12" Hifonics Hfi dvc's in a sealed box at 2 ohm.

I was thinking that the 4 12's would hit harder and deeper but they are cheap subs and the G5's are great subs. so im kind of lost here....

I will post pics later when i get my camera if you need them...

Oh yea both setup are going to be in the trunk facing the trunk (back)

I would love to hear anything/everything good or bad you guys got to say...

Thank you...