Monroville posted this on another thread, but I thought the pics would be good inspiration for possible visuals for the NPT
http://www.chrisfoss.net/gallery1.htm
http://www.altanen.dk/Gallery-Main.htm
If we intend for the modern Imperial forces to resemble the Old Republican forces, these are probably not the best designs for that, but brightly painted Mandalorian pirate ships would look pretty nifty.