Almost all of the items on there are maintenance items that need to be done anyway.
As far as the steering, you might just need a new steering damper/stabilizer. If you replace it get a Bilstein. It's a few bucks more but well worth it. Steering Damper/ Stabilizer
Search for parts as an Mercedes-Benz SLK 320. I like FCPEuro because shipping is free after $49.00 and they offer a lifetime warranty on almost every part they sell.