Did you say you had the Tamiya two channel adapter? I usually scavenge mine for the plugs.

One of our club members uses a two channel setup on his sherman and from what I see, it is a pain in the butt. Spektrum DX-5e or Futaba 4yf 2.4ghz are only $95 new and may save your sanity.

OF COURSE, THIS IS ONLY MY OPINION. Try a local hobby shop that specializes in R/C, many former FM users are trading in their radios for 2.4ghz and the used equipment is real cheap!

Another thing to look for is the surplus DX-5Es from the larger Park Zone RC planes. I picked up a radio and reciever for $80 that came our of a Corsair. The buyer had a Dx-7 and got a deal minus the single reciever DX-5.