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..
Cheapest: tweecer
Easyist to install: AEM and Tweecer
Most features: AEM and FAST
Easyist to tune: it's all what you are used to, you can call the FAST and AEM tech line, but there are whole Fourms dedicated to Tweecers
yeah its all about cost, who is going to be tuning, and what your perameters are. I know there is more systems like big stuff III etc.
it all depends on what your plans are, and where your going with the car, if your not using monster injectors and a return style fuel system a tweeker seems to be your best bet....