The 3.6 conversion is of the M103 block out of a 300E or 260E. 190 2.6 applies as well I suppose... Conversions of the 3.2 DOHC engine are also possible. Actual output wont be 350HP naturally aspirated. To get into the 350 ballpark you will have to add turbos. To get a AMG engine, call AMG. Go to
http://www.performances.com It is a Canadian distributor of AMG stuff. I believe the person you want to talk to is Eddie Lai. (sp?) You can always keep an eye on the back of the Star classifieds. Sometimes exotic tuner wares (like AMG engines) come up. The classifies of Autoweek are not bad either.
Hope this helps...Lee