Are all combi boilers also condensing boilers?
Looks like BB is against condensing boilers fitted loads , as long has you get a good make , Vaillant / Glow-worm Ect do not buy a cheep one, Your Choice will be limited if fitting LPG I would advise against messing with LPG this is a very Dangerous Gas. It is against Building Regs to fit a non condensing boiler, if you are found out you will have to remove it! also all boilers have to be registered with Gas Safe / Building control, You need to be Gas Safe to do this, also you will invalidate your house insurance if boiler is not Registered and if you sell you will need registration document. BE WARNED DO NOT MESS AROUND WITH LPG GAS HIGHLY DANGEROUS !!!