It's already fine as it is. The slots are already enough to fit every KOF char. that appeared in the main series.

Converted to 1280 x 720 since it's Mugen's default resolution. I actually have much more space now. Also, I resized the portraits to normal standards so you don't have to change anything if you want.

http://img.photobucket.com/albums/v154/mgbenz/Mugen/kofim_new05.png

Open in new page since it's huge.