I've built up two Ritchey Swiss Crosses recently at home during the pandemic. Ritchey 1 got GRX600 and Easton wheels, Ritchey 2 got Chorus and Hunt wheels.
The fork is easy to install as the fork race is built in and the cups are integrated. You just drop the bearings in and thats it. I have all the headset tools at home but none were needed.
The bottom bracket is standard threaded so that's pretty easy to do on your own also.
If the fork is cut, make sure you have enough length to make it work for you. If you don't have a torque wrench, you should get one, the seat tube crushes if you torque the front derailleur past 2Nm, which is super low.
FYI, the frameset includes the frame, fork, headset, and axles; I'd also get new since its on sale.