1024x768 is fine but I will need some smaller ones. I am going to be using it on a multisync monitor. Any chance you can make it a Scalable layout? Scalable layouts will scale to your selected screen resolution automatically. The only thing you have to consider is the ratio of your screen resolution.
• 1.33 (4:3): 320x240, 640x480, 800x600, 1024x768, 1280x960
• 1.25 (5:4): 400x320, 640x512, 800x640, 1280x1024, 1600x1280
• 1.6 (16:10): 480x300, 960x600, 1280x800, 1920x1200
• Free aspect ratio
That means a layout for 800x600 will also work on 640x480 and so on.
This was taken from the Mala site