yes, TT91 has one, stand alones are the way to go if your changing your combo alot or like to be able to tune on the run, they use a wide band, which makes life easier. Im sure he will chime in. If your going all out hit up the new FAST it supposed to be easier to use now (software wise)
and if you need any help tuning or want to talk to a pro with stand alones PM me and ill give you the guys number who programs mine. He is the best in the area for our cars..