Excuse me as well Cracker. This is to Lady birder, but should apply to you as well.
LB, you need one person only to oversee this project. Don't try to engage all the different trades yourself unless you've had experience of doing so.
A local small building company , or even a good one-man-band.
One local builder will have a list of contacts, people he's used before.
He'll have tame plumbers, electricians, tilers, carpenters etc etc.
They'll refer to him during the work. You don't want to get involved in possible problems directly.
A decent trader will bridge between you and the various trades needed. They'll talk the same language.
...and, you won't be stitched up if you choose your guy carefully.
Local recommendations as always :o)