Interestng little tid-bit regarding LiLPG.
If you get one of these systems made up, they currently NEED to be dual fuel, you will need to start up on petrol for 30-40 seconds then switch over to your LiLPG system.
The reason, I am told, is that the LPG will vapourise in the lines when not in use, thus no fuel on startup.
I would imagine they will find a way around this... in time