I'd put 6.5 power valves in it. If you want to drop the secondary PV that fine. I am not a huge fan of secondary PVs, but they can have their place in a road vehicle in certain cases.
If you use a secondary PV, I would start with 81 or 82 all around, if you drop the secondary PV, go with 81 or 82 In the pri's and 86s in the secondaries.