If you want to do it like they say, otherwise anything with the right fitting is fine, and depending on what kit you bought you might already have something. Although you've already bought a kit I can recommend the stuff from http://www.epicbleedsolutions.com/ for being cheap and as good as anything else.
I take it the threading on the shimano is not the same as the avid then... Have an avid kit... Actually just realised that I don't want to cross contaminate dot and mineral oil... Might just buy another avid and hope I don't need to bleed anyone else's bikes :)
If you want to do it like they say, otherwise anything with the right fitting is fine, and depending on what kit you bought you might already have something. Although you've already bought a kit I can recommend the stuff from http://www.epicbleedsolutions.com/ for being cheap and as good as anything else.