Is there any way you can save up a little longer and get something nicer? With tack you pretty much get what you pay for.. And everything you have posted I wouldn't get near a horse I was riding within a 10 mile radius (except the stubben).
If I had known you were looking when I bought my Stubben, I would have picked up the other one the lady had for you! Heck, she might still have it. It's an older Stubben Siegfried with an 17.5" seat and a medium-wide tree (fits my Aires great with maybe a little room to spare). The one she has left doesn't come with leathers, irons or a girth, but she only wants $250 for it. I could ship it to you. Would you like me to inquire after it?
This is the fully fitted-out Stubben Siegfried (18" seat, but same size tree) that I got from her for $275. It's slightly older than the other one she had, but the second (newer) one is in just as good of shape.