Good cam choice. Don't go bigger.

Use the aluminum heads. They won't cost you much more than redoing the 346s.

I hate the heavy stock 440 pistons, but if you are buying a kit try to get the Six Pack pistons, L2355F or something like that. They have a compression distance of 2.05, that will help build compression.
DO look at the KB pistons, they have a couple of nice slugs. Everything else you mention is good, if you can afford the Perf RPM that's the one, if not then the CH4B is miles ahead of a Performer, and shouldn't cost an arm and leg. The stock cast iron intake and T-Quad can work too. Put your upfront money INSIDE the engine, intake manifolds and carbs can be upgraded later.
At $165 the Firecore distributor is an easy choice.

Find a pair of HP exhaust manifolds and go 2 1/2" back with an H-pipe and my favorite Dynomax Super Turbos, the 17748 or 17749.
Why H-pipe? It's less expensive and gets the job done. Nothing wrong with the X, but one can fabricate and install an H in a short time.

I'd keep the 2.94s, it'll be a great cruiser, and FAST on the highway.

R.