I can definately provide you with a relay setup to solve your problem...however you sound like your tech savy yourself so I believe if you check out www.altronix.com you will find your solution in a vast inventory of simple and multifunction relays with trigger inputs that accept 6-12VDC. A simple solution would be to use a simple DPDT Latching relay board with a 12 or 24VDC coil and a 12VDC + or - trigger input that can be directly connected to the 12 V trigger output of the projector (this relay would be used to power TWO polarity reversal relay modules that are controlled by the "raised" limit and the "lowered" limit switches. When in the raised position, a 12V trigger on the relay can only supply the polarity to lower the lift by actuating the "lower" polarity reversal module and visa virsa when in the lowered position. For this to work properly and for long term you would want a quality high current linear power supply which could feed the relays and your motor and you would also want two limit switches on each the raised and lowered positions. One limit for activating one of the polarity reversal circuits and the other limit to reset the latching 12 VDC trigger relay to kill power to the polarity reversal module powering the motor. The next time the trigger is applied to the latching relay the process starts over and feeds your motor the proper polarity to either raise or lower the lift depending on which limit is active. The site www.altronix.com you will find everything you need including a power supply. I hope this info helps, with this kind of setup, you will have a pretty decent lift. I also agree with you that the most stable method is to use the trigger output from the projector eliminating the reliance on IR or RF. Your parts would run under $100 USD and would fit in a small chasis on your lift or away from your lift with the proper wiring.