Scripley,

I got the head studs from Automotive Racing Products.

http://www.arp-bolts.com/

They don't have any mercedes applications on the shelf. I had to bring them one of my head bolts along with a number of measurements off the motor. Luckily they had an application on the shelf that was compatible with the dimensions required. If you have to get a set custom made the cost won't be worth the benefit. If you email me I can send you a pdf of the measurement form they use. If you call them they can walk you through it.

As for the head, it depends what the condition of the head and its components dictate (as well as your wallet). In my case, the car was burning a lot of oil and finally I blew the head gasket. As a result, I had the valve guides and valve stem seals replaced. I reused the valves as they are very expensive and mine were in good shape. The valve springs were going soft (150,000 miles) so they were replaced and a light surfacing was done on the head. Total cost was $500 for the parts and machine work.

Good luck on your project