Pipedream have a new 853 Sirius. Looks quite nice indeed.
Reynolds 853 butted main tubes
Traditional 'A' - seatstays
Gusseted HT/DT/DT junction
Bridgeless chain stays
Double bent stays
Sliding dropouts
Clearance for 2.5" tyres
269 quid!
http://pipedreamcycles.com/sirius_page_menu.html
Being a 631 Sirius owner, and more than happy with it, the new variant look rather decent on paper and in the pics.

