As I mentioned in an earlier missive, the "official" Wings of War \ Wings of Glory models are usually rather nice (not the Sopwith Triplane - more on that later possibly) but they don't cover all the aircraft wargamers would want, and even when they do, they sometimes do them in some strange colour schemes.
Sometimes the solution is easy - want a Red Baron Albatros DIII in all red, just get the Brumowski DIII and overpaint the skull - job done (well in theory - in practice finding one now at a reasonable price is rather hard because they were all bought up and repainted...) However some easy conversions are possible just by adding some decals - step forward the talented Dom Skelton and his little on line shop Dom's Decals
Dom provides a series of self printed water slide transfers for use on various scales and themes, including WW1 planes where he does generic national markings but also some unit specific sets that allow you to create squadrons or Jastas. Dom also supplies the official WoG models at very reasonable rates and is highly recommended.
I should also mention an ebay shop I have used - 1:144 Direct, who also have a line of nice decals.
Using these decals for the first time can be a bit daunting as they are a single sheet that needs to be cut out, not individual decals like you get with Airfix models, and they do take a bit of preparation and care in applying - RTFM is recommended, but you can get some very nice results.
Lastly - what about aircraft that have no models at all? Look to the Future - 3D printing! I vaguely understand how this works, but to all intents it may as well be magic. Shapeways offers a 3D printing service that while it has its issues, shows how this really could revolutionise gaming miniatures. There are hundreds of WW1 models available and the prices are quite reasonable. I could write a tome on the subject, so I think I will save that for the next post, but if in doubt have a look again at this Albatros to see what they are capable of