If you want to save weight and have an overall goal of maybe making a 1-2lb difference. The cost goes up a lot as you throw in a lot of light weight goodies.

I.E.

Lithium Ion RX battery and Ignition battery
3 x power regulators
Carbon fiber wing and stab tube
Carbon fiber landing gear
Carbon fiber spinner

You can spend a lot in a hurry on trying to save weight. Try cheap ways first, like switching to Kavan wheels or using some foam wheels. That will save you maybe 4 oz.

Tom offers fiberglass landing gear which is much more robust than carbon fiber, lighter than the stock gear, and looks good to boot!
I really dont see anything wrong with a simple setup using Nimh Rx packs. Get comfortable flying the plane and then decide if you want or even need to loose a lot of weight.

Tom will have much better deals on a lot of things then you could buy from a hobby shop. Not sure why people dont ask him first for things. Even has some hard to get engines!