check out
this site for the basics.
For the areas that say "bios dependent" can be ignored. Almost every bios you can find can do those.
In my opinion, the "x-ecutor 2 lite" is the best for use. If you want something more and accually know how to flash bios onto a chip, then I say go for the "xodus". It is a no solder chip that is easy to install. If you don't mind soldering and want a chip as good as the xodus, but can hold 4 different bios (which I have no idea why you want 4), then choose the "x-ecutor 2 pro".