I am not personally a fan of the system. I suppose it's an ok place to start, but keep in mind that you should be playing fewer O8 hands than hold'em hands and you should only be playing 15-20% of your hold'em hands. You really would be best off getting Ray Zee's hi-lo split book. It doesn't have a specific ranking chart (there's no such thing as far as I've found) but it provides good, solid info that can be converted into pretty specific guidelines with a little thought. Check out steve badger's website (don't have a link, sorry) for a good primer as well.