suggestions for my 340?

Cam kits;

Cam kits come in various levels. They can be as simple as just a cam and lifter package or one that has everything you need and then some. The cam, lifter and spring package is the most basic starting from zero package I listed and doesn't cover all the bases that may need to be covered.

I suggest reading how to rebuild your small block MoPar as well as How to hot rod your small block MoPar. Also the factory has a book designed just for your w time that can be purchased on line easy enough.
It's called the engines book.