LPG Conversion - How do you choose?

[PhilCerbera]

Any experts with advice on the best system (not cheapest) to fit to a newish V8 Range Rover 4.2 supercharged? Tartarini and Prins seem to be favoured, as does BRC but I can't differentiate the technical pros/cons from the information available. I gather the Tartarini system is sequential, are the others? How do you differentiate/choose?

Also experienced converters local to me are quoting up to £1k difference in price to supply and fit.

Any pointers please to help me make the decision.