Definitely invest in a lipo if you plan on going brushless in the near future.

When I got back into RC last year with a B44, I bought a good NIMH saddle. Then a few months later, I went with a lipo, and the difference in punch and speed was really noticeable.

Also, you may want to get a 2.4ghz radio system as well to prevent any glitching issues. I was using an AM radio with brushless and it wasn't a good combination.