Greg, I saw two on e-Bay today (e-Bay USA) but the asking price was over £20, more than what I'm prepared to pay for what is, having built one earlier in my modeling career, a pretty sh*tty kit... Nitto and Doyusha had Concorde in their ranges, both of them prototypes. I had Nitto's once, but never built it.
The only (I believe) other Tu-144 on the market is Academy's, but it is scaled at 1/360 or something silly like that. It's the Tu-144D rather than the pre-production or the prototype (as VEB's).
As far as VEB is concerned, I've got their Mil Mi-10, plus the Dassault Mercure, a Yak-40 and a 727-100 (all started). Never saw their Il-62 though. Must be a pretty impressive piece of plastic!
Oggy - no, I do not know of any An-225...