scytek am or fm?

Hi!, I have been reading this forum for a long time now, and this is my first post, i have never had to post anything as most of my questions have already been answered in other posts, and most of them really well answered, but this time i have 2 questions that i havent find an answer to.

The alarm im looking at is scytek Galaxy  5000RS-2W-M, im looking at this because it is for manual transmission and i like the features like in car temp, remote starter, and good price,  and i have hear many good comments about them, my last questions before buying would be:

1.- is there any diference between the AM and FM version?, if the only diference is range, how big is it? because there is a 60 dollars diference between one and other that i could spend in a tilt sensor instead.

And my question 2 would be, how well does scyteks channel expander works with this alarm, does it connect with the brain with a network conection and how difficult is to use the extra channels with the lcd remote? Well thanks you in advance!!

No one knows anything about?