You should use an internal pump if you can find a good solution. The best solution is an internal pump that is also regulated so the return is inside the fuel cell. That way you get rid of the return line and an external regulator. Holley sells those setups so see if you can find one that works.

You'll need to sell your MSD distributor and buy a Holley Hyperspark distributor. The rest of your stuff will work okay. The Sniper needs 12 volts cranking and starting but your MSD should already be wired that way.

The Sniper will work just fine on your engine. Buy the Stealth model if you have a stock throttle linkage. The regular Sniper is wider and the stock throttle linkage doesn't fit properly.

You will most likely need to use a laptop to fine tune the Sniper.