Can anyone recommend me a good strong light wheelset for city-ridden disc MTB?

I ride an MTB bike to work and back, 15 miles a day. It's already evolved to be a fast bike, with big front cogs and a tight back cog. I only use it on roads in London.

I need to replace my wheels. though maybe only my back, and want a

For £200, you could get one built to your own specification.
The last wheels I had built were £120 for the rear and around £85 for the front, but that was about 3 years ago.
I have an MTB based hybrid, with disks, and the wheels on that

UBC MTB CARBON WHEEL TESTING IN WINTERBERG DH / BLACK TRAIL Varus

Testing of MTB_Prototype_Carbon_Wheels at DH_Track in Winterberg in July 09. Fully Carbon Wheels with size of 23-559 and weight of 1550g/set ...

Easton Havoc DH Wheelset- First impressions | News | mountain bike ...

Easton's new Haven carbon wheels are getting all the attention these days, but riders looking for a solid set of wheels for downhill and freeride applications would do well to take a look at Easton's Havoc DH wheels. Each component of the wheels is well put together, as is expected with a wheel set at this price point and caliber. The concept behind the single butting was to retain spoke material close to the hub for a strong and stiff wheel that would accelerate and brake quickly, but minimize the rotating weight. First impressions of these wheels have them riding and performing as good as they look. First impressions of the wheels back that up. They get up to speed fast and feel solid, even when braking in burly terrain. The no-nonsense black and red graphics compliment almost any ride, and the straight pull spoke design has been proven to create a solid structure with minimal stress points. The Easton Havoc DH Wheels. The straight pull spokes are single butted, and retain a......