I have found the same and it is a nightmare trying to sort the wheat from the chaff of online guff websites.
In the end I used the Green Building Forum as my starting point and then took recommendations from there. The problem is trying to find anyone who offered the 'big picture' initial options discussion - which it sounds like you are after at this stage.
I was surprised how little incentive there is for doing this sort of thing given our future eco obligations. The cost of installing a pellet boiler for example was nearly 4x the cost of replacing our existing oil boiler with a new oil fired version. Absolute madness in this day and age.