Mountain Biking UK's Doddy fell in love with Mavic’s tubeless EX823 rims in Whistler last year. They’re not cheap (£73 each) and the unique cradled nipples need Loctite to stay put, but they’re incredibly strong.
The tall hub ﬂanges mean you can use shorter spokes to create a very tight wheel, maximising the 150mm width spacing beneﬁts. They’re light for a big body unit as well.
We went through a set of the super-smooth German bearings on an early rear hub fast, but this set has been ﬁne and the fronts are well sealed. Make sure you really tighten your cassette down though, or the splines can scar.