There is a nice Pitts available at Avsim, and I've heard rumours of a new Sukhoi under development at the moment I've not seen an Edge, and you have an Extra in FS as one of the default planes. What is wrong with it?
Ozzy
There are two types of aeroplane, Spitfires and everything else that wishes it was a Spitfire!
The Pitts that Ozzy mentioned over at Avsim are really very good. You can snap roll them and do hammerhead stalls on a dime. They're all for FS2002 but they work very well in FS2004.
There's a new freeware Pitt out from the Bulldog Airshows site that I picked up last night. It's a more modern version and with more hp and speed. Looks pretty good too.