You mention that you've already got the haltech ecu ya? If thats the case, maybe check if you're actually running AFM now. The models seems to be able to run on map sensors but maybe the map sensors are additional items which users have to purchase seperately (like de-jetro, ecu itself is around 1k and if you include sensors looms etc the real cost of the package is around 1.7k).
In any case, tuning a car without afm takes longer according to a couple of tuners. It can be done but if you're not after huge power (imo anything above 500awhp is huge), I personally wouldnt recommend map. Like what Eugene said, why pay for something extra which you dont need?