My suggestion (it is what at list I do)-build unit yourself. There is allot of people claiming they know everything and what they sell is the best on the market.
ALL B...S.
Even most knowledgeable members, I seen so far, like Bio and Myold, admitting that in field of HHO we still need to learn allot to be able to use what mother nature gave us.
There is allot of good info on this forum. Enjoy reading and knowledge you can get here. If you going to buy, it will help you allot and if you going to build yourself, it will help you even more. Check this post by Bio
http://www.hhoforums.com/attachment....9&d=1300660896 .Very nice design and allot of experience he put in this unit. This is my 2c.