JeffeVerde

I've got a 40-year old pool, plumbed in 2" copper with bronze gate valves. The stems on two of the intake valves are stripped, and one of the return valves is iffy. The way the intake manifold is plumbed, I'll have to sweat off all three valves to replace the two bad ones. Likewise for the return side. Given that I'll be removing all of the valves from their stubs to get to the bad valves, I plan on replacing *all* of the valves so I don't have to repeat this exercise in 6 months. Since I'm going to have 80% of the above ground plumbing apart, I'm wondering if there's any benefit to replacing it (the above ground part) with PVC and Jandy valves. The materials are about a wash, on bronze vs. Jandy valves. I think I could build two PVC manifolds faster than I can sweat off five 2" bronze valves, and I'd upsize the manifolds to 2-1/2" for better flow. Will the Jandy's do variable flow-control the way a gate valve can? Or are they more of an on/off valve like a ball valve? What about Jandy 3-ways vs 2-ways? The way the stubs are layed out, I could replace the existing five valves with three 3-ways, and still have all the routing options the five singles give me. Would a 3-way Jandy provide the same flow-balancing ability I have with individual gate valves (e.g. balancing main and skimmer suction for good skimmer performance, and trickle-return to spa to keep the spa turning over)?