If you have the 6/7 kg butane or propane they are in the same group of bottles so can be changed for calor lite propane in theory. However...... Some suppliers are only changing lite bottles for lite bottles due to high demand of them. Might be worth ringing round a few suppliers first to see what their own policy is at the time. Some are letting you buy them under a new agreement but not swap them too. Tried a few suppliers before being able to swap our butane and a propane for 2 calor lite. I think once you have them, there's not so much of a problem getting hold of them. Hope that helps
A 10kg capacity Gaslight weighs about the same as a 6kg Calor Lite so if weight is a consideration a single 10kg bottle might be better than two 6kg bottles but obviously you then have the downside of no spare. All depends on what your needs are and what is available where you might need to get a full bottle. If Gaslight was more readily available I would change to that but as it is I would struggle to get it within 15 miles of where I live.
------------- 'A sure cure for sea-sickness is to sit under a tree'
Safefill refillable cylinder, 15ltrs/8.6kg of propane (auto gas) weighs 15.7kg full with a cost of £13.04 (can be cheaper) to fill with 8.6kg of gas.
Very safe to fill, they cut of at 80% full and if you forget to close the cylinder valve when disconnecting from LPG pump, no gas escapes, 2 very good safety features and you can always go off with a full cylinder, just top it up as and when.