Hiya and welcome!!

While you can cobble together a system (with the exception of the transmitter crystal, which FCC regulations require be tuned to the unit), to reduce the number of problems on your first system I suggest you purchase an entire package, which will include a transmitter, receiver, transmitter and receiver batteries, charger and servos... Tower Hobbies is an excellent mail order vendor, whose selection of radios can be found at:

http://www.towerhobbies.com/listings/cat-cat-j.html

Complete systems can be found on ebay, but in the unlikely event there is a problem, service can be a headache...

Depending on what your plans are in the hobby, a 6 channel radio system will likely do everything you need for at least a couple of years, which is an eternity in the development of radio systems... If you buy an upper end 9 channel today, by the time you are ready to really use it, there will be better systems available...

Which brand to buy is a matter of personal preference, and may be influenced by the other pilots at the flying field you will be using. If you plan to have them help you learn, having the same make system will make using a buddy box possible...

Do a search on this site to see what others are saying... Good luck!!

Cheers!

Jim