I believe the Ultra Sport kits are still available from Tower if you wanna build a kit:
http://www3.towerhobbies.com/cgi-bin...?&I=LXJ583&P=7
http://www3.towerhobbies.com/cgi-bin...?&I=LXJ584&P=7
-OR-
The Tower Kaos 40 comes to mind as an ARF:
http://www3.towerhobbies.com/cgi-bin...&I=LXZT80&P=ML
I would think your in pretty good shape given the list of planes you have progressed through thusfar and the Dirty Birdy should actually fly better...The ole Ultra Sport would however get you closer in the speed spectrum and offer the "flying on rails" attributes of your Dirty Birdy...
Oh BTW:
The Dirty Birdy should also be available from Blue Jay Models too (forgot about that)...I can't get their website to work at the moment but they still sell allot of the Bridi kits to include the Dirty Birdy...Hopefully they are just working on the website??
Welcome back!!
Chuck