simple enough...If you're gonna run a typical bosch relay like this one

just run circuit protection to 87a from b+ and make this your high current circuit. Run the high current wire from cavity 30 to your fuel pump.
power cavity 85 from the circuit protected ignition feed off of your ignition. Run 86 to a dedicated ground. another method would be to run cavity 86 to a 2 pin oil pressure switch so it would only energize when cranking or running.