Giant Octopodes

Greetings! I'm building an Adeptus Mechanicus army (yeah I know, but I didn't know when I picked the army, the codex wasn't even released, it was a snap pick with no knowledge of the rules or armies when I got back into the hobby based on lore, style, and background). When it comes to basing, I'm trying to do a relatively simple, traditional Mars basing scheme, especially because I'm a basing newbie. Beyond just rocks for accents, I'd love to throw around some skulls and bones. I think it perfectly fits the character of the army, the idea that biological leftovers have no value to them so they don't even bother burying their own fallen, they just chuck the fleshy bits out wherever they're found, take the mechanical parts, staple a new organic in, and send them back out there. Skulls are readily found in abundance. I have a box of skulls, and there's endless bits and stl files of them around. Bones, so the terrain is not just weirdly all skulls, are surprisingly difficult to find. I'm hoping for pieces of skeletons, whole skeletons, random parts of rib cages or whole rib cages, and arbitrary bones. Obviously just whole skeletons that I can then cut up would work perfectly well also. I'm planning on half burying them in the terrain, with just bits and pieces poking out, so it's definitely quantity over quality. The "Beveled Bases: Bone Fields" are kinda perfect, but for a few nagging things: They're all the same, whereas I'd love to have each model somewhat random and unique in its basing; they're overly abundant in terms of bones per base, where I'm just looking for accents not necessarily the whole base; and they're only available that I could find as finished products at a very high cost, while I'd love either a bag of parts or STL files. Yes, I know I could make my own bones, with toothpicks and / or green stuff, but it's equally fair to say I could make my own skulls... if I had any modeling skills of any kind. I sadly do not. Does anyone know of anything available commercially, or have a DIY product / method which even a total rookie with feet for hands and minimal time available could utilize? Any insights or assistance is greatly appreciated!