Originally Posted by DimSum
What kind of maintance costs am I looking at? Is it easy DIY-able (oil changes and filters)?
That was why I said check this side of ownership out before jumping the gun. Anyway engine related on a 911 is a major job and shouldn't be done by yourself unless you are highly skilled. If not using the main dealers then look for specialists in your area as they usually work out cheaper (i.e. closer to BMW main dealer prices) as for part, well I wouldn't personally chose anything other than factory products, after all this isn't a joe-average 3 series we are talking about.
May I suggest you checking out specialists in your area and seeing what they quote on parts, service etc.
They are truly brilliant cars either of your choices but regardless of what price they are secondhand they are still a Porsche and their ownership costs are still gauged accordingly.
Winter driving : the 911 is OK but it's main problem is width of rubber and ground clearance, so best stick to main roads when ever possible as you will get stuck for sure.