The shop will not do it for you for 1 simple reason: liability.
For the law, it could be true but who know if you have it in your car. But if you have accident (jumping car) that cause by remote starter, Insurance may or maynot cover the damage. You may double check with DVM or local/state police/trooper to see whether it is legal or not. There are some remote starter (with/without alarm) that design for manual trans. To use it you have to follow several step before you get out the car so that you can remote start next time.
I installed it in my Supra and never have any problem with jumping because I put 2 extra switches by the shifter (front and back) to detect wether the shifter is in gear or neutral. The car doesn't have neutral signal but clutch signal which I bypass by the remote starter output signal and relay.