The Vortex GlassPak may fit the bill. You can get one on ebay with a Vortex Dakota Tripod for $70. The tripod alone is worth more than that. I recently picked one up and am pleased so far.
I think that is going to work. I went ahead and ordered it this morning. I am going to use it on our carbon fiber tripod.
We have been kicking around building varmint shooting benches that are much more portable than the four we have now and we want infinitely adjustable legs on them. I think this set of tripod legs will provide me with impetus to get started on that project. Our current benches are fantastic, but they are a PITA to haul further than 40 yards or so from the truck. We have been wanting a couple packable benches for about ten years now and I am going to lam up the tops from 1 1/2" rigid foam insulation and 1/8" Baltic Birch plywood. I want the leg sockets recessed, so that may be a bit tricky fabricating the sockets for the legs.
The last thing we need is another set of tripod legs, but the price on this set makes me want to get going on the prototype lightweight benches I have been procrastinating on.