geotect first of all is this the plant your looking for?
http://www.desert-tropicals.com/Plants/Agavaceae/Agave_americana.html

And I KNOW! I'm gonna get flamed for this.... easy please people that read this, they are for sale in AZ, larger ones are pricey that's one way to put it. As far as I know they are not endangered or regulated. If I am wrong I know I will be swiftly corrected here. I have been lurking for year's because of that. Flame me but please don't turn me over directly to the feds.

geotect they are in my yard and pup alot in winter... I am also not at That home now but will be then. Best time to uproot them anyway. Bad news is..... they are not light weights they are bulky and heavy we are not talking S.A.S.E. here.
1 to 1 1/2 footer's my 'pups'..... they grow bigger that 3 feet I can tell you. Send me an e-mail maybe we can make a trade.... find me live Ube, and I will pay the postage.