You are getting the horse ahead of the cart. If you don't know how to get scions you also don't know much else about growing fruit. You need to get a good tree and get it started. the size of tree you start with isn't that big of a deal. Just get something from a reliable source like Adams Country Nursery or raintree nursery. Potted trees are not better then bare root. Stores like Home depot are not reliable in giving you what the label says. If you are in the midwest, red haven is a good choice but there are others. And it does vary by region.

No need to add any other varieties until next August, and you would bud graft. between now and then you are getting the tree shaped the way you want it and learning as much as you can about peach trees

Keep reading this forum.

After you get your tree established, their are lots of people who will trade you scions of different varieties on the plant exchange forum. For example, I have an elberta peach variety, an unknown peach variety, and a variety with more than one type. This year I traded for some peach, apricot and plum scions using my elberta cuttings for trade in order to expand the varieties that I have. I suggest that you research the types of peach trees that do well in your zone and buy that one as your root stock.

Thanks Charlie, I'm thinking of Reliance for my 1st year. I have never done grafting so that will be new for me. Are peaches like apples in growth habit? I usually plant 3'-4' stock and then prune at 3' to start my framework.

I'm pretty new to this site and I'm very pleased to see you can trade scions here. I'm guessing that fall is when trading starts?

I'm about 50 miles from Stark Brothers and I bought my apples from them since my gas was way less than shipping. I've seen lots of suppliers in Tn but being able to hand pick has trumped their lower prices.