I have a Tactical Tailor pack, not sure what model it is. They make two different size assault packs, a small one and a medium one. No, I think they make a large one too; they have a lot of options actually but there's really only gonna be two you wanna consider I guess.. I have 'em both but the medium one holds more and also has straps on the sides in addition to molle loops. Both can be made to clip onto a larger ruck, an assault vest or body armor, without the use of the straps.
So what I've been doing is just using those side straps and pulling 'em tight to hold the tripod to the side of the pack. I have a Sirui that's pretty compact too, your length more or less depending on setup. If you wanted, you could get a carrier or bag to fit on the molle and do it that way too.
Tactical Tailor also custom makes and modifies things, their store is right by their shop more or less. They make good shit too, very popular with soldiers from Ft. Lewis, rangers and SF guys too, especially since you can get stuff customized. You could probably get a zippered pocket stitched on one side for the tripod with the molle shit on the outside of that. Or whatever.
The backpack itself also has a place for a 3L Source bladder and outlet for the tube (and holds the bladder and it's weight up high so it's not sagging to the bottom) adj., padded straps, 3 compartments, a large orange panel in the large one, etc. Water resistant nylon. Great 3 day pack if tend to carry a lot, could go twice that long if you don't. Very well made. Probably $150? $175? Just guessing. I know it's a bit more than the small one and it was about $100 or $125.
Another option is a "radio ruck". It's a heavily modified ruck (if you get TT to upgrade it) made to your specs. It attaches to the aluminum ALICE frame. But you could have molle loops put on the ruck, Velcro, whatever. They do a LOT of these, especially for sniper teams (sometimes to actually carry a radio). They have more room than a 3 day or assault pack, but are quite a bit smaller than a full size large ALICE ruck. Inexpensive, and the frame with a smaller ruck and lower weight is actually comfortable on the back. I have two of these actually, neither upgraded, but still useful. So lots of options just from TT.
Worth a look/phone call. I love mine and have never needed another.
