In all honesty IMO this way works better than the Stans kits way because its seals up non tubeless tires better. It doesnt work better than actually tubeless rim which while spendy are a ton better for doing this and you dont have to do it the ghetto way. i have literally 1000s of miles on this setup on various rim/tire combination on trails all over the country. The failures have been few and far between and when it fails I just put a tube in it. On shorter rides where I cant get stranded in the wilderness I dont carry tubes with me anymore as my chances of flatting on nearly zero.
It doesnt matter about the wire vs folding just be very careful of using ultra lightweight XC tires, because some of them just do not work. For instance the standard Small Block 8 can be a bear to seal up but the tubeless version of it works just fine.
http://www.epicski.com/forum/thread/95039/how-to-do-ghetto-tubeless-for-finndog-and-anyone-else-who-wants-cheap-tubeless-tires
those picture work in that thread.
I use schrader valve because it easier to seat the bead with schrader valve and it also means that any old gas station pump will work to seat the bead with out an adapter. If you use 'tubeless" tires you will most likely be able to seat the bead with a floor pump. Presta valve do work and I have the same set up on my Single Speed cross bike and my road bike with prestaa tubes albeit running a tubeless hutchison bull dog cross tire. I did not want to drill out my skinny cross/road rims.
as for tube size here is my list
26 inch rim = 20 BMX tube
650B = 24 inch MTB tube
29er = 26 inch MTB
36er(yes they do exist) = 29 MTB
editted to add this
you can not run higher pressure with tubeless. 35 psi is the max I go with non tubeless tires because of the risk of destroying the bead of the tire and also blowing it off the rim, You can run higher with tubeless tire....but the point of going tubeless is to run a lower pressure with out a risk of flatting.
My reference. The bolding was by me. I believe seating the bead is not the same as the bead hooking into the slot in the rim.