Radioshack has a similiar screw driver that is smaller, but the body can also be used with an awl blade. It doesn't give you quite the range of bits, but it takes up less space and manages any pair of glasses and non-torx tiny electronics I've ever seen. As limited as your space is, I might suggest seeing what bits you need and don't need for the leatherman as well not carrying the spare saw blade for it- you already carry a better saw. In the same vein, I might also delete the wire saw. I say that as someone who carries a bunch of tools in my kit as well.

I might also suggest picking between the heatsheet and the mylar bag. For the bulk, the heatsheet is probably a better choice.

Swap the tent stakes for some nails with the tips filed dull- works just as well, and a little smaller without the hook. And with a file and rock, they turn back into nails.

How much more space did you want to add? Maybe the Emdom Baby UtiliShingle on the front might give you enough space, if you have a small FAK in mind. The other shingles would give you more space, but more bulk- call the dice and throw 'em.