the Haltech version is just basically a Racepak IQ3 with the haltech channels already programmed into the dash (comes with 16 pre-programmed and 3 "custom" channels which you can choose). Can support up to 32 different channels/sensors though. If you wanted something for your AEM you'd probably be better off with the regular Racepak IQ3 and i'm sure if you talk to racepak they can provide you with the interface to suit your ECU.
I really cant wait to get this up and running and start playing around with the software. Going to be a fairly steep learning curve I think.
Also with the turn signals, I dont believe racepak can do it. It has 4 warning lights and sequential shift lights but I doubt these can be wired up to be used as other signals.