Hi Runic112,
Welcome to the forum.
Are you going to keep that tree in a pot ?
You can either pot it up or put it in ground right now. Just don't touch the roots; leave them as they are .
That tree looks great, you made a nice choice.
As for choosing it all depends on your budget and on what you are looking for.
As general rule, I try to be under or around 20€ per tree. Then, I try to buy them bushy and not as a single trunk - because I'm in Zone7 and I need to cope with winter die-back.
Then I try to buy them leafed out to avoid buying a dead tree.
In a group of tree, I take wether the bushier or the stronger with the more stems and leaves.
Of course criteria number one is the strain :) , unless I'm gambling on what might come out of that tree because the tree is cheap.