http://website.lineone.net/~rmtucker/
2nd row, 3rd picture. There is a thread here on this machine, the builder is rmtucker I believe.
You won't get very good performance from the FET board, btw. You'll get much higher speeds with a Xylotex or the new Hobby CNC board.
If you do want to use two motors, you will need a 4 axis drive. There are a lot of machines that use 2 motors per axis that work fine, they just have to be well designed and setup. You want to make sure you NEVER miss any steps or you could cause some damage to your machine.