Hey guys hope all is well. I just picked up an 06 Duramax Dually with 140k miles. It's all stock. I'm starting off with a 2 car hauler and once I get my CDL ill move to a 3-4 car hauler. I'm looking for a package that gas HP/TQ and MPG as my main concern. I know basics like intake/exhaust/tune but which ones? I'm not "ballin" yet so I need mid-grade quality because I don't want to spend too much cash. Suggestions??