I would go with a flat washer and a lock nut, not a nylock, and some locktite. Lock washer will break and fall in the pan causing the pick-up to rattle. For the pan gasket don't for get to drill out the end holes so the bolts fit.
Real Nice Stainless Engine Bolt Kits (http://www.mmsacc-stainless.com/html/ford.htm)