If you are using UFH, its more normal not to use wood in the floor structure. Wood is a good insulator - no good for convecting heat from a floor, for example.
Concrete > insulation > UFH > SCREED > final surface.
Such that the UFH is embedded in the screed.
Electric UFH will be astronomical to run. As with any electric heating system. And elctric UFH frequently goes wrong. . .
As Ban says, use a wet system. It will probably be cheaper to install too. And you can rig up any number of fuel sources to it. Gas boiler, Ground source heat pump, electric boiler if you want to stay in the dark ages, oil boiler, aga, back boiler, coal fire, you name it. Much more practical. Nobody fits electric UFH to a whole house,its just stupid.