Hi, what I did to start a car where the driver lost the keys, I replaced the ecu and the key immobiliser along with the ignition barrel What I did was removing the battery, removing the ecu, left the car with plus and minus probes connected between them for about 20 mins, replaced all the parts, connected the battery, ignition on for about 5 mins (the engine managed light was on), turned the ignition off for about 10 mins, and after it started. You don't have to replace the alarm as it is a separate circuit. Hope it helps. The only problem would be that for a future owner if he/she wants to buy new key from the delay, the code won't be useful. If you want to do it, try to find one that comes with the small metal plate that has the manufacturer's code on it. Hope it helps.
I've done the cam belt 3 times on a voyager diesel including one time with the water pump (which was actually fine with 130K miles) it's a time consuming, but not too difficult job. You need a set of timing pins to lock the engine and cams in place, but other than that just normal tools.
Took me all day to do the belt and pump, about 5-6hrs to do just the belt...
