ORIGINAL: JIMF14D
Check ebay for a while or Tom's RC online. Hitec optic 6 2.4ghz $133+$40 for 6 channel rx roughly. Probably find DX6i for near $150 if you shop. Maybe less used on ebay
Forget 4 channels if you want to grow to anything and want seperate aileron channels. spend a few dollars and go for 6.
Excellent advice here.
Karol