The AR500 will work with no problems as it is a full range DSM2 receiver but is only a 5 channel receiver, but since you have the DX6i why not spend the extra $20 and get and AR6200 6 channel reciever? That way you have enough channels to keep up with your radio. If you want to stay with JR/Spektrum servos the [link=http://www.horizonhobby.com/Products/Default.aspx?ProdID=JRPS8411]DS821[/link] is the standard digital servo and runs $29.99. But if you don't mind getting away from JR you should seriously think about the [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LX0929&P=SM]Airtronics 94102Z[/link] standard servos for $11.99 each. I have over 100 of these and they are just about the best standard servos you can find. They are reliable and work extremely well.

Ken