marydell | Knitting machine query

Do any of you knitty types out there use a machine? Are socks made on a different sort of machine than sweaters and scarves?

Charlie's prosthetic arm goes over a sock, and the only 100% cotton ones are big on him and sometimes get folds in them that translate into lines on his skin. I'd like to be able to make him some that are fitted to him, and are in a really soft cotton, instead of relying on what's available. Since they can't have seams I can't sew them out of existing tights or socks, and since they need to be really fine gauge I can't hand knit them (leaving aside that I barely knit). I don't have a problem buying a machine to do this--after all, he'll be needing these socks for the rest of his life, and he may as well have them in fun colors if I can do that--but I don't want to get the wrong one. There's this "ultimate sweater machine" thing that doesn't seem to be inclined to do socks, but I haven't seen an "ultimate sock machine" so maybe I'm just not getting it?