Small ported SQ box in an SUV will be very very difficult to do.
First off, subs really don't care what kind of ported box they're in. You tune the port to the enclosure's volume and not what subwoofer you'll be putting in it. Some companies may recommend one thing or another; it really doesn't matter.
Here's what matters; port velocity. Smaller boxes need much longer ports and you can get into issues with the ports making noise do to friction. You usually won't hear this in a trunk; you'll hate it in a hatch/SUV. Larger ported boxes need shorter ports and don't suffer as much from port noise. For SQ, you want a vented box on the larger side.
What I'd recommend is only 1 12" subwoofer if space is the main concern. It'll still have a lot of output but it won't take up as much space. It'll probably have more output than a pair of sealed 12's anyway.
Figure out what you want to do with your hatch area as far as a box goes before you spend $600 on a pair of 12's that might need a HUGE box to minimize port noise and sound terrible when they're sealed.