As far as I can tell, the 715 doesn't share the exact same front spring mounting configuration as any of the other Jeeps. All of the early Jeep trucks, including the 715, had the "post mount" type springs, but that's where the similarity ended. The Wagoneers were spring under, like the 715, but the springs were much closer together. The J-trucks were spring over. BJ's Offroad is currently developing some lift springs for the early post mount Wagoneers, but I doubt they'd do us much good. In the future, they may develop some for the early J-truck, but who knows if they will come any closer to the 715 stuff. I doubt it. The lift kits currently available for the later FSJ's have a completely different mount. Any way you go, you're most likely looking at custom spring mounts for any off-the-shelf spring.
If you can get custom springs for $180 ea, that sounds like a deal. Like tacoma says, the increased arch won't flex as good as a flatter spring, but the stock springs are so stiff they don't flex at all, so you may actually come out ahead!