well the torx socket head sockets you might be able to find something at sunex tools, they make excellent impact sockets

as for this half moon socket your looking for?
i assume you are wanting it to fit on the head of the bolt side that looks like a flat semi half moon shaped head? As far as i know there is no socket made for those. They are made flat and have splined shanks and the head is round with a flat side to grip the rim so when the nut is tightened it doesnt slip.
I think i know the problem your having in some cases that when your trying to loosen the nut to pull the rim apart the bolt starts spinning because the rim is worn out at the hole.
Well as i said there is no socket made to fit this side of it so like toyota and tcm said... you will need some good vise grips or some other way to grab ahold of that side of the bolt and hold it. Use some penetrating oil to help loosen the nut. In some cases i've actually had to use a good sharp chisel or a cutting wheel and just cut the bolt out of the rim because they were rusted or cross threaded and just would not come loose, they would just spin around.
I think you're going to have to improvise on this one imo because i've never seen a tool for that part of the bolt head.