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=) Thank you. I looked and only found super flimsy ones or a couple that were in the $300-$400 range. Way more than I want to pay for a travel setup.
You could go with one of the Leica heads, which are sturdy but very compact. In an even smaller size, you could put a 1/4-20 platform on a RRS BH-25 or BH-30, which will keep the price down.
Something to consider: Though a D700 + 24-70 isn't especially demanding in focal length, it is in weight. A heavy lens without a tripod collar will be more cumbersome to use than an even heavier lens that can be properly balanced. Because of this, it's really helpful to have a larger ball with more gripping surface.
To keep costs down, you might consider something from Photoclam, which gets good reviews around here.