After going back and forth on different options for the wheels - rebuilding the Kurushiro Enso rims, finding a nice second hand set of wheels, going 27,5 inch - I settled on last option. From what I have read, 27.5 rims with 3.0 tires have almost the same diameter as 26 inch fat bike tires. Also, with wide enough rims you can still fit 4 inch fat bike tires. The latter will have a slightly larger diameter than the 26, so fingers crossed this will fit.
I bought a set of second hand rims that came from a Tune Blackburner Enduro wheelset. Inner width is 42mm and weight is just shy of 500 grams.
For the hubs I am considering buying a pair of White Industries Snowhite hubs. I found a store that has these in stock in the polished edition. They can sell it to me with a handsome discout, but even so they are about the same price as Hope Fatsno hubs. Unlike the Hope hubs though, no XD driver option available and no way of ever upgrading to thru axle. They do look nice though.