Unfortunately I do not know how to take a picture with a white background and make the portrait with the white background(unless you want that although that would look ugly) but a few days ago I made my own portrait for Bushwhacker and happen to come across your need for a Bushwhacker portrait.here it is!--->
now what I am wondering is why you didn't just make your own portrait.At first I thought it would be hard to do but I watched a 7 min video and found out not only was it very easy to do,but it takes MUCH less than that.It literally takes less than 1 minute(less when you get the hang of it).I'll show you how in a quick tutorial
1.create a new image in Gimp(as I do not know if it has the same options in Photoshop) and make the Width 120 and Height 140(when you do you will see a white box)
2. Drag and drop desired image in Gimp
3.scale photo so it fits perfectly in the white box
4. Click on layers>transparency>Threshold Alpha
5.click Layer>Merge Down
7.Now go to File>Export... and export the image as either.PCX, .BMP or .PNG(as those are the file extensions Fighter Factory recognizes)
8.now open up Bushwhacker's .DEF file in Fighter Factory and go to his big portrait that you are going to change.
9.Click change and find your portrait you just made
10.Save all and enjoy!