340 oiling system

You've read the threads on the pumps. So I'll just give you what I'd do - assuming you are haveing the crank machined and the rods resized as part of the process.
Have the machine shop deburr the valley area of the block and drill a few extra oil return holes up there. Have them enlarge the oil feeds from the camshaft galley to the main bearing saddles to 9/32". Use the stock pan, use the factory windage tray - but pry open the slots another 3/16" or so. Set the oil clearances up on the .0015-.0025 area and run the 3/4 groove main bearing set. Run a std oil pump with the MP high pressure relief spring package and a new oil pickup. This will let you disassemble the oil pump to add the spring pckage and inspect/clean it. You should not try to clean an old oil pickup. You may lossen up debris that was safely stuck in it and it will get sucked into the new pump. Save the $30 somewhere else.
That will give you a solid oil system that will take anything you will throw at it.