Recommended Building Suppliers & Tradespeople Gatwick Area

abankerbutnotafatcat

Hello everyone - my first post!!!
We're just about to move into a new house in a new area - it's a substantial Victorian property whereas before we were in a low maintenance modern, purpose built flat. We're planning to get some work done and have obviously watched too many eps of Rogue Trader etc because we're paranoid about encountering the cowboy element.

Can anyone recommend any good tradespeople/building suppliers servicing the Gatwick/Reigate area in the following fields (we're not going to do all this at once btw!!):

General Building/knocking down a structural wall etc
Loft conversions
Granite worktops suppliers/fitters (I wonder if the fabulous Alan who is in my area will see this!!)
Wooden Flooring
Underfloor heating
Kitchen installation
Electricians
Insulation
Heating Engineers
Specialist (probably spiral) staircases
People who maintain brickwork/external window sils (not sure what trade this is)

Thanks in advance for any recommendations!!