I put ~570bhp through a triple box 2 7/8" exhaust at 1.6bar on the 67DBB and it was very quiet, so you'll probably be fine for a while on that exhaust mate.
I'd make sure you spend money wisely on the best ECU, injectors, plugs and mapper you can find - that's what will keep the engine safe. I'd stick a single Bosch 044 pump in the tank and use the stock line to the fuel filter and the stock return from whatever FPR you run. Make up some dash 6 lines to feed your new fuel rail from both ends and then call it good. That'll see you through OK for low 600s anyway.