We've been in a similar position to rogerangie, so feel their pain! Builder's merchants have been the answer, here in West Yorks, we use Dixon Hall. Keep the receipt and they give 10% discount to returning customers.
Well we should be ok, we have a full 7kg butane and a full 6kg propane. Once the butane's used up we'll replace that with another propane and we'll run propane permanently from then on. Can't be doing with having to change the regulator and unscrew the cooker burners and switch them round when we switch gases.
We had considered the Calor Lite cylinders but with the recall meaning there's a shortage actually in circulation.....