Changes to the Building Regulations (effective from April
2007) require that in virtually all new domestic installations
and boiler replacements which use oil, a condensing boiler
is the only type permitted. But you may be exempt from the regs hopefully.
There is only one boiler manufacturer I would recommend and that is Worchester they are the best in producing oil fired boilers and have been for a lot of years I would go for the Worchester Greenstar Camray 18/25 Regular as a suitable replacement for you're existing 80,000 Btu's Boiler, but this is a condensing boiler. If after the survey and you find that you can install a non condensing boiler then fit a Worchester Camray 5, 65/90 Regular RS/CF boiler.