My usual guide regarding hand fly vs. anchor flying a kite goes a bit like this. Look at the required or intended line weight. Then step on a scale. If line weight exceeds your personal weight, then that kite can take you out if hand flown. At the very least, it can force you into a situation where your options are let go or get dragged. This is not a happy place. So, I anchor anything over 200# line weight. Also, on larger kites, I usually fly with the next stronger available line strength above what's recommended. I just like the additional margin of safety, and large kites can handle the weight. There are great suggestions on anchoring on the links others have mentioned.
As for larger delta kites, you will find all sorts of nice ones on the links scrolling just to the right of this very column. Into the Wind has many to choose from.