Here is a cheap, light hub with dimensions similar to an Alchemy front: http://www.bikehubstore.com/SuperLig...b-p/slf78w.htm. It's made by Bitex. I have a set of wheels with A23 rims and they seem a bit heavier than advertised, maybe more like 440. It doesn't bother me, but if you are looking to build a light wheel I don't want you to be surprised. Since you have a DT rear I would consider a DT 415 for the front.

As I mentioned earlier www.psimet.com is custom builder who frequents these forums. He has a good reputation and prices and builds with all of the brands we've been talking about. I'd ask him for a quote.