There are so many good commercial sources, I'd recommend buying from reputable nurseries. While noid is correct regarding the vinifera vines, there are some excellent hybrids available that negate the need for grafting. Granted, a few hybrids will actually benefit from grafting (not because of low phyloxera resistance, rather because a few type's own-rooted don't seem to exhibit adequate vigor), but in general own-rooted will do quite well. You can buy cuttings, but rooted cuttings put you and your vines so far ahead of the game that you'll quickly realize that the few bucks saved wasn't worth it.
Miller's, Stark Bros., and Double A Vineyards (not necessarily in that order) come to mind; while I like Double A, they tend to have a lot of early sell-outs even though they carry an enormous selection.
Also keep in mind that a part of the reason they won't give you cuttings is that some varieties are patented, and unauthorized propogation is a crime. Not saying that's what's going on with your local vineyards, but it is a possibility.
Not all hybrids will give you the foxy/skunky hybrid or labrusca aromas or flavors. Coirot Noir comes to mind; it also has an excellent tannin structure. Traminette is very much like one of its parents, Gevurtztraminer, but survives the winters here in 4B/5A, and also has an uncanny ability to adapt to its environment in such a way that, as long as the zone, temperatures, water and growing season are at least within reason of its needs, the acid-sugar balance is just about perfect. Chardonel, a cross derived from Chardonnay, also does well here, and I've have had good success with Chambourcin as well as Cynthiana (a decidedly American, and decidedly excellent, red wine grape).
If you get your own rooted vines to start with, and they're not protected by patent, you can make all the cuttings from your own vines that you'd care to and that the prunings will allow once the canes are large enough for making cuttings. And while there are many ways of propogation by cuttings, some are better than others. My personal opinion favors the process of inverting the cuttings in clean sand (to keep what will be the vines cool and out of exposure to the sun) while exposing what will be the root end to a relatively warmer temperature and exposed to sunlight until the callous forms and rootlets begin to develop. This is necessary in order to give the roots a head-start and get them growing before the buds break and begin to demand from the root stores what they haven't even got yet - heck, unless you're doing it this way, there AREN'T any roots yet.
Anyways, all of that information is out there and easily found by searching. No point in me going over it here.
I also grow Concord and King of the North (a naturally occurring labrusca-riparia hybrid). This year pretty much everything around me for a long way was frozen-out by the late cold and snow in May, but the Concord was still on track with almost 50# per vine! The King of the north was way down, I think I only got about 14# per vine but the quality was very good. All my grapes went either into wine (varietals, if you will) or into meads/pyments. It's going to be a good next couple of years as everything matures in its turn.
