If you are running the FS-WWI 1.6.0.7 Beta Patch there are widescreen resolutions. Sadly, all OpenGL32 resolutions have to be hard coded in (That's how the engine was designed)...
Glad you are now enjoying it, mostly CTD free!

The Farman III is very nice to fly. For some hilarity give the Santos-Dumont a try, you will curse all the way down to the ground.

I wish we had a turn-of-the-century Englad/France terrain! Sadly, none was ever made as this is a combat flight sim first...