I'll have a look to see if I have any pics of the AT6/Texan/Harvard/SNJ in ther colours you want. If not, Eric (Evangilder) might have something.
The best maximum size for pics here on the forum is around 800 x 600 pixels. If you're having problems re-sizing, I can recommend 'Irfanview'. It's a FREE to download programme, and easy to use. Just select 'Image', key in the size you want (only need to input one dimension, eg 800), click on 'OK', then go to 'File', click 'Save', click the confirm windows which will pop up, and that's it.
Hope this helps.