Luckily there are 6+ channel hobby grade receivers and transmitter packages that are less than $30. It might be worth it to save yourself a large headache and try that. You should also try talking to YHR about using a BARC4 or a DBC system too, they are pretty cheap and do a lot. HL receivers can be found for CHEAP and the hobby recievers to attach to the RX18 are cheap as well. You would be surprised how little it takes to get going

Give YHR a PM and let him know what you are looking for.