Get yourself some of EAST COAST YEAST's "Old Newark Beer" strain (as opposed to their "Old Newark Ale" strain).
It purports to be the same yeast that the Ballantine Brewery (Newark, NJ) used for their "lager" beers (including their bock beer).
It is actually an ale strain, but a very neutral one.
It's a terrific yeast.
Available periodically from Princeton Homebrew (in Trenton, NJ) as well as Love2Brew (North Brunswick, NJ)
Both shops do mail order.
disclaimer: I don't work for any of these companies.