rover 400?

rover 400 developed a fault whilst driving it started to llose power become arratic over the last week. now whilst driving it has died. the fault is electrical i have checked the obvious ( rotor arm, leads, rotor cap,spark plugs ) no prob found now that only leaves me the following as far as i can see.
1. ht coil failure
2.ecu failure
3.maybe a relay failure
4. imobiliser failure .
i do no have any ignition spark ???
can you help please