Yep, Paul will hook you up with exactly what you need, OM a great choice for the tank.
Do whatever you want with the bulkhead gaskets, you dont need silicone, but silicone is a great "safety net" to use. IF the manufacturer of your BH's say dont use it, then dont. I guess these other guys tighten the bulkhead fitting like a gorilla and squeeze the gasket out, if you dont overtighten the gasket, then you will not have this problem, even while using silicone. Its funny how one group says dont use it ever, and others use it all the time. I gues its like a friend says.."some like Fords and some like Chevy's".