it is a jungle out there, and $700 is not really enough to get a top end setup, so you will have to compromise. I agree on the height, and its tough to find good legs that sit that high for less than about $400-500.
Don't be afraid to buy used either.
I'd place priority on a high end head with arca swiss plates,
RRS, Kirk, etc. You can often find good strong Bogen / Manfroto aluminum legs that are built like a battleship for $50 and less on Craigslist. Just pass on a Manfrotto or Bogen head, or resell it if it comes with the legs. The QR plates for the heads are non standard, and can release if not carefully secured, dropping a camera off the tripod. You have to be uber careful, one slip, and you have a head that may have cost you $1000 in camera / lens damage.
I bought two sets of $400 Carbon Fiber legs from Benro. They met all my requirements for height, strength, and functionality, but when I went to buy a part, I found that parts are and were never available for these, so if something breaks, I could have expensive scrap. I also bought two Benro heads. They were the worst junk I've ever owned, and are just sitting here, because I don't want someone else to get stuck with them. I then found a used Kirk ball head, its wonderful, no comparison.
Buy a good head, good used Aluminum Bogen / Manfrotto heavy Aluminum legs, and then save for good legs. Those 25-30 year old Bogen legs are often as good as when new.