Just buy another Spektrum receiver...like the AR6200... bind it to your Radio. If you want to get into 3D type flying, get a couple of digital servo's, they tend to have faster transits and are more precise than analogs, like the Spektrum/JR 821's ($29.99)...Hitec servo's will also work fine with the Spektrum system and are usually a few dollars cheaper than the Spektrums

Edit: The DX6i is a full range radio