mine too has a limiter if i'm not mistaken it kicks in at 200km/hr but i've only been up to 196km/hr :D so haven't tried it out yet. will try it out once i have a safe location
i've read from rx8club that the normal fob remote is compatible will some alarms though but if you gonna spent money maybe spent it on a 2 way, but maybe not with remote start as u know u need to clutch in before you start.
there's this guy here selling radiostar 2 way alarm i think u might wanna contact him its approx Rm600 for 2 remote and an alarm system u might wanna do a search on it