Electric Fuel pump
I do not have a oil pressure switch on my electric pump setup. Didn't feel it quite necessary, i have a gauge and an idiot light for oil pressure. I like to hope i can turn the key faster than my carb will run out of fuel in the bowls before it dies. But, to each their own!
Whichever route you go, you should really wire it into a relay. With the proper gauge wiring.
And as far as the stock sender, heading to your local lowes/home depot brass fitting section, you'll be able to find various bends and tee fittings to make something work
-Mike