turnigy 9x is very good for its price. i've been happy with it for all my planes. but currently having troubles with quad copter and its rx connection and calibrations (see my threads if you want) on the APM2 board
the turnigy 9x tx takes (with slght mods and a squeeze) a 2500 mah lightmax transmitter battery avail from hobbyking
I second the Turnigy 9x (or the FS-TH9x which is the same). A company named FlySky is the original factory. HobbyKing rebrands this as the Turnigy 9x. The only difference other than color and label is HobbyKing places the antenna in the traditional location and FlySky has the antenna mounted on the TX module on the back of the radio. Cosmetically, the Turnigy 9x looks better, but unfortunately the antenna is soldered to the TX module. You can't remove the TX module without cutting the antenna. The FlySky version is truly modular. It's not really that big of a deal. Just a small hassle factor.
Regarding upgrading the firmware. This is highly recommended. The work the teams at er9x, open9x and Gruvin are doing is great. The factory firmware on the 9x covers the basics, but has a highly annoying beep every time you press a button. Upgrading the firmware adds a crazy amount of additional functionality (and removes the annoying beep). You can find out all the details at the link I posted above.
If you are interested, we sell a solder less 9x DIY Upgrade kit (programmer, backlight, upgraded, thumb sticks, neck strap, etc) at parkeflyer.com. It's everything you need to upgrade in one simple package.
After you get your Turnigy 9x, this may be a good option for you.
We also sell a rechargeable battery with the right cables you need to plug directly into the 9x without cutting or splicing.
Ping us if you have any questions.