The primary points to look at when radio shopping: you want it on 72 mHZ, you'll need mini servos, and receiver (but try to get micro), and you want a dual conversion receiver.

Those are the very basic things to know. The stuff that follows can be ignored if you wish.

The receivers (rx's) with "limited" range are single conversion. Limited range is a minor fault; the real problem is they're not very good at filtering stray radio waves, like pager signals, and can result in the demise of your plane. In my opinion it's worth the extra $50 to save a plane.
Dennis-