How much higher will the floor be? it looks roughly 2" in your pic. If you relocate that little black box with the foam around it you are easily able to fit a full size 10" in each side. these are the ones I put in my car with the floor raised 2" Clarion Canada | PXW1052 (Outside Dimension 10 3/8" Mounting Depth 5 1/2")

Ohh I was just checking out the specs on you amp and subs, check out the RMS.
Sub - Power range: 50-250 watts RMS @4 ohms
Amp - 600 Watts (RMS) x 1 @ 4ohms

Might want to get a smaller amp or a little more powerful sub. Bigger is not always better.
Just my 2¢