wow, those metal MAK-esq figures are great, although small as you say.
The 1/35 figures are too large, although they would be awesome as a smaller walker.
The Alterra figures might be the way to go. Pity that the SAKS figure is not for sale, the other two have pretty weedy legs, and the opening hatch for the head is cool too.
Another thought that I had was kitbashing GW Tau Stealth suits with marine legs, although that would be a little on the large size. (Stealth suit body, marine legs, marine arms?)
If I were a little bit better at sculpting, I could have a go at making a torso, and then cast it myself. Slightly beyond my abilities I think.
Thanks everyone.