I originally wanted to get a PRP bench for the rear, but was urged to go with the same seats as the fronts.
I was told not to bother with the bench because I wanted more room to fit adults in the back comfortable enough for long days on the trail. That would require a bench seat narrow enough to fit in-between the rear wheel wells and roll cage. And I felt it more comfortable for passengers to have two separate seats, over a bench. If you need to fit three back there, you may be better off just keeping what you've got, because the aftermarket bench seats I've seen, on PRP brackets actually give you less room than the factory seats. The shop I go to fabricated mounts that gave me maximum leg and head room.
Absolutely love how it turned out and only wish I'd have done seats years earlier. I did not get the recline seats because the cage has horizontal bars behind all the seats for the harnesses. All seats also have heat.