Neil,
I, for one, am extremely sceptical about the value of UV in this application.
The dust mite is photo-phobic, so retreats from daylight into the depths of the wadding. The penetration of the UV emitted by the equipment is limited, consequently its' efficacy.
Undoubtedly some of the mites drawn toward the surface will be effected but it has yet to be demonstrated that the total kill-rate is significantly enhanced.
What is important is the use of a powerful, vibrating vacuum device. Ideally this would be powered by an HWE located outside the building. I have built an electric power head for this purpose but a good turbo-head would suffice. Remember that a dust-downer will also be required to protect your HWE.