There's plenty of mortgage calculator templates available. Plug in a couple of scenarios (non-fixed term rate, remortgage with current provider, offer 1, offer 2 etc) and work out which is the best deal for you.
Likely that the base rate+ model will either work really well or not work at all. If it's close, just go for the long term fixed.
The spreadsheet is your friend.
There's plenty of mortgage calculator templates available. Plug in a couple of scenarios (non-fixed term rate, remortgage with current provider, offer 1, offer 2 etc) and work out which is the best deal for you.
Likely that the base rate+ model will either work really well or not work at all. If it's close, just go for the long term fixed.