iv got a datatool 4 on mine, cost me £300 fitted but i got £50 off my insurance, its got motion sensor an all that, no remote start up though, id be weary of that incase you ever left it in gear! i as told they are actually illegal on anything with gears and are only meant to be fitted to automatics...
Got a Datatool S4 on mine as well. Had a Meta M357Tv2 fitted to my last bike. I've got no complaints about either unit. The Datatool has a 'hazard light' function that's not on the Meta but other than that there's nothing between them.
I've got the Scorpio sr-i500SWB with the TRS-6 black waterproof remote. I think I got it from Absolute Cycle Performance, it was VERY cheap as compared to other sellers (especially Kneedraggers). It came with the bike specific harness and all the options.
for the most part you can add any alarm system you want. it doesnt necessarily have to be for a bike. The only things you might use are the ignition kill and the proximity sensor. And i agree with the dont put a remote start on your bike (bad news bears). if you accidently leave it in gear, you have just screwed up your bike.