I'm still with FS2002 (no intention of going to 04!). There is a FS2000 Concorde updated for FS2002 in the downloads pages (use the search function) - also, there are some repaints available there for Virgin and Qantas, if that turns you on.
If the flight dynamics aren't what you want, then I suppose you could always try using the Microsoft model, but with the Mach 2 Concorde flight dynamics. Haven't done it myself, but there's no reason why it shouldn't work.
Have fun!
