When I did my water pump last year, I bought the Laso. Still seems to work alright, although I would check on what the MB part is going for, in case it's not too much more.

Your car probably has the updated hose connections for the new water pump design. I think the breakpoint was somewhere around '87 or '88.

I would also seriously consider buying the Snap On tool. You don't have to, but considering that doing this job yourself probably saves you about $500 in labor charges, the $50 for the tool is well worth it. It only swivels in one axis, making it more stable than a universal, and it has a really short socket, which lets it get into all sorts of places that a conventional socket + u-joint struggles with. Oh, and it's a 12-point socket too.