the socks I've been using for my PT 2nd job that requires up to 24,000 steps per shift have been Craftsman Men's 2pk Steel Toe Boot Socks. they came in white & black. they have extra thick toe & heel sections. can't find them anywhere anymore tho ...
but these look like they are worth a try
FoxRiver Heavyweight Steel-Toe Crew Cut Socks (2 Pack)