I went to that site and it came up as a laundry list of mushroom sites, kinda like "bizrate.com with no specific "kits" to buy. If you really want to get seriuos about being a "kitchen chemist" go to Mycotopia.net. Search the archives and ask questions.
But... I will tell you this much so far; mushroom kits are a waste of time and money and you most likely will result in contaminated, rotted product. The production of magic mushrooms is a very long drawn out, labor intensive, detailed venture that requires specific steps in a specific manner under near sterile and sterile conditions within a set range of temperatures during various stages with a through understanding of such. That is why we are called Kitchen Chemists.
By the way: 3 pounds dry weight will mean 30 pounds wet/fresh. That equates to about 40 grow boxes that are 2ft x 2ft x 6 inches high. Each 1/4 pound typically involves 20-22 hours worth of actual work (doing stuff) not to include the 5-6 weeks of wait time from the initial innoculation to harvest.
But if you need help down the road... give a holler.