Planned on mounting it using 2 lock blocks on the stem with a shim if necessary. The one you linked to looks pretty good, any real difference between that and the $70 models: http://www.dealextreme.com/details.dx/sku.18071?

One other thing, is there a reflector or something that can be rigged up to stop light going into the sky and on-coming drivers eyes, at 900 lumens that can't be too good?

Thanks