Doh, haven't checked this thread in ages. It's probably too late now but I got them from here:
http://www.carbulbsdirect.com/product/xenarc-cool-blue-intense-d2r-single
Yeah they're bloody expensive.
They're listed as 5000k most places. However, supposedly they were reclassed as 5500k at one stage. They look very white - touching on blue-ish.