I want to build my own wheels.

What I got so far are the rims: https://www.flybikes.com/product/fly-lunar-lite-rim-black/RLRL03

And some potential hubs: Rear: https://www.tritoncycles.co.uk/components-c9/hubs-and-spares-c120/hubs-c591/surly-ultra-new-rear-disc-mtn-hub-p9851 Front: https://www.tritoncycles.co.uk/components-c9/hubs-and-spares-c120/hubs-c591/sp-dynamo-pv-8-power-dynamo-ultra-small-front-hub-p11398

I would like to get some sapim spokes but all the online calculators online are failing me because I cant find all the data points they ask: https://www.sapim.be is there an easy way to do that? Should I order the components first and measure them myself? (I felt that is kinda risky as I want to make sure everything would be compatible first)