Ah, fourwinds, you went through the Warren Gregoire "interview" ;-) ! A 12" unipivot sounds like a fine arm choice; London’s throwing a lot of mechanical energy back into whatever it’s mounted on, and can cause any but the best bearings to rattle. Warren told me the current London’s need the same arm as any other high-quality cartridge---medium effective mass, a stiff arm tube, and good bearings.
The owners manual with the current London’s gives recommendations for resistive and capacitance loading. I believe the Super Gold is spec’ed at 22k ohms resistance and 220pF capacitance, but some owners prefer the standard 47k ohms. Another thing to keep in mind is that the Londons put out a very high 5mV, so a phono amp with very high overload characteristics is a real good idea. They need no more than 40dB gain, and low-gain phono circuits typically have higher overload margins than do higher-gain circuits, a happy coincidence.
What the London provides in spades, even in comparison with far more expensive pickups, is an extremely dynamic, immediate, "live" sound, making many others sound anemic, bland, restrained. Boring!