You can pick up the Duo-Q for really cheap (around $15 I think). I bought one used off of someone locally with an ICEDCUBE silver replacement case for $20. It is basically a clone of the XenoGC chip which is also cheap. They don't offer any extra features just booting from DVD backups. Some of the better chips have upgradeable firmware and the ability to load dol files from the firmware without booting to a disc.
It's pretty easy to install. You just remove the dvd-drive and solder it to the bottom. The Duo uses wires the Xeno has solder points that line up to the points on the board. There are 6 wires + 3 more if you want to attach the LED which shows you the status of the chip. I didn't bother with the LED board but might hook it up later.