Oil Filter (Fleece Type): MANN HU 718/5 / NAPA Gold 7078 / WIX 57078 (I wouldn't recommend a filter element from any other supplier unless you want to purchase a M-B filter element; Lots of sellers on eBay and/or internet vendors with MANN filter element.)
(Note: M-B states that the filter element made of paper is acceptable on the NA (Normally Aspirated) 3.2 Liter V-6. However, most of us use the fleece-type filter element which is the recommended version for the SRT-6 model.)

Oil: Mobil 1 0w40 European Formula / Mobil 1 5w40 ESP (Lots of choices that meet M-B Spec; Look for 229.3 / 229.5 spec on the back of the oil container. Lots of European-sourced cars use this spec. I've got single quarts of 5w40 Synthetic Castrol that I use for our VW Beetle. Meets the same 229.3/229.5 spec. Slightly lower price at Walmart than Mobil 1. I buy my oil at Walmart, which is one of the lowest prices around. Get a 5-Qt jug & 3 of the qt bottles (my preference). 8 Qts will put the oil level on the dipstick at FULL mark. And I don't have any partially full containers around after the oil change, which is every 2 years for me. My $0.02.

With my driving habits, I perform an oil/filter change every 2 years. And I still don't reach the 7000 mile oil change interval. Just don't feel like going past 2 years with the same oil in the car. Attached are a couple of M-B spec sheets for recommended motor oils.