Possible = probably
Practical = doubtful
Is there a kit? Ask yourself the question, how many people are moving gas cookers from the UK to the USA and would it be worthwhile for a manufacturer to even contemplate having a conversion kit to support this? I would guess no.
I would guess again that Propane is Propane in both countries.
Because the voltages in the UK are twice that of the US the elements and internal wiring will be of different specification - for the same heat output, in the USA twice the amount of current needs to flow.
You may get away with a properly rated step-up transformer to convert the US domestic supply from 115V to 230V but the cost of the transformer may well approach the cost of a locally purchased American cooker.
If the oven's clock/timer runs at an interval based on the supply frequency (it probably doesn't) then the clock will run 20% faster in the US.
What an excellent, technical challenge you have.
Peccavi
July 2009