I need more awesome garden space

Is a blueberry bush usually a very large plant? I need to know if this image here to the left is typical of what I'd get, if I walked into a nursery and asked for a blueberry bush. They didn't have any blueberry bushes at Lowe's today, which was a bit disappointing, because we're on the hunt for one. Sydney and I decided some time last year that we needed a home-grown source for blueberries, but knew we'd have to wait until this spring to get one.
So, here we are, because it's spring in Arizona, hunting for blueberry bushes. But again, I wonder if they really come -- blooming as well -- in this smaller size. I don't want to plant it in my backyard, because we want to take it with us when we move, so it'll have to be somewhat portable. I've got a relatively large pot ready for it, too. This will be a task for our Thursday, I think, since we need to find a flowering plant for Sydney to take to school with her on Friday anyway.
BACKYARD UPDATE: I had to buy bug spray for my roses today, too (which is mainly why I went into Lowe's), to get rid of the aphids all over them. And my orange tree is still kinda smelling good, but now I wonder if I'm going to get any oranges. The rosemary plants are growing nicely, and there's fresh growth on my gardenia (despite Oliver peeing on it occasionally). I'd like to trim some of the purple, flowering tree's branches to clean up the aesthetic, as well. Finally, I think even the plumeria will see some happy growth, now that it's getting warmer.