Sorry, didn't see any sections for newbies.....

Just bought this one today and I've got a few thing to research on here for the solutions to problems..... i.e. HVAC blowing only hot air and adding keyless entry.

 

The obvious is to have the A/C serviced. At least needs a charge unless something else it faulty.
For keyless entry you need to fit both doors with actuators, inside control on the arm rests and the receiver plus a hand transmitter and figure out the harness integration.
I believe you will need to address the use of the GEM module unless you make it a stand alone job.
Get all the hardware form donor truck in a yard.
My opinion is it's not worth the hassle unless you make it from after market simpler hardware.
Good luck.

 

Heard so many horror stories already about worst case scenario a/c fixes of the blend motor and blend door :-(