I think the I think the Black would be overkill, especially if you are running it through the 400's phono stage. In fact, if that's what you're doing, the P5 is overkill, too -- though that's my kind of overkill!
I would go with the Bronze. You can always upgrade to the Black stylus anytime.
The 2M is a very resolving series of cartridges and it has plenty of high frequency detail. I think it would balance nicely with the rest of your system.
As far as surface noise, however, the 2M doesn't perform as well as some low-output moving coils in the same price range but it is state of the art in terms of moving magnets. Again, if you're using the Fisher's built-in phono stage, a low-output MC isn't an option anyway.
No spacer necessary -- unless you have a thick aftermarket mat or something. The entire 2M series was designed around the Rega tonearm family from the RB250/251 on up.