I've bought a Force 10 charcoal barrel style rail mounted BBQ. They do
gas as well and have a website with dealers. Windscoop, not sure where you
live but www.westmarine.com is where I got mine.
Magma make SS gas BBQs that are excellent, available from UK chandlers but cheaper from West Marine USA (they are made there). Gas cannisters are not the usual throw aways but have a valve fitting so can be removed for stowage. This makes the cannisters expensive. We converted our BBQ with a regulator/hose from West Marine and a UK end fitting to go onto a normal cylinder, propane preferred but butane works at lower heat. We use a red Calor propane cylinder to run the BBQ, refills cost about £9 and last 2 seasons! We cook a lot on the BBQ, it works like an oven and you can do a full roast dinner inc roast spuds very quickly but do use a meat thermometer.
Wind scoops in UK cost about £30 from chandlers, about £22 from French ones,