Finally got this built up, after a lot of shopping around and deal hunting, which was made harder by the current situation as everyone is buying bike stuff.
Spec is a bit of a mix of Shimano 11 speed kit, with last generation Ultegra shifters and crank (50/34), current 105 FD and cassette(11-34) and GRX 800 series brakes/RD. Wheelset is from Prime, currently with some 32mm continental tyres. Clearance is quite tight!
From a short ride outside my house it feels great, a big step up from my old bike. Still a bit of fettling to do, but looks good so far.