Your charger should be OK.

Do you want more flying time?

Radio manufacturer battery packs are way overpriced and often not great quality.

Check out Radical RC and Hangtime Hobbies. These guys run small shops and do great work spending the time to make their packs right. They only use Sanyo batteries which are basically the best quality. Prices are very good, especially Radical RC.

I wanted more flying time on my trainer so I bought 2100 NiMH Rx pack and 1650 NiMh Tx packs from Radical RC. Hangtime sold me an overnight wall charger with 120mah output on Tx, and 180 output on Rx. It is $18 I believe. No need for field charging equipment and I can fly ALL DAY!

The cost btween the NimH and NiCd is not much and getting something over 2000 mah is not much more either.

I would go with NiMH, Rx pack over 2000, Tx with 1500-1800 (Tx drains batteries less quickly so you can use lower capacity packs on them).
Your wall charger may not fully charge something over 1500 but for $18 yu can get the one at Hangtime Hobbies.

This was the best thing I've done and the most cost effective.