Re: wiring
If your Strat uses a standard 5-way lever switch, you can split all three with just one push/pull. You just wouldn't have individual control over them.
Run the red/white combo of each pup to the associated terminal on the unused side of the 5-way. Run the "common" terminal of that half over to the center of the PP, and take the lug above that to ground. (Just like normal split wiring.)
Each pup will now be split when it's selected, and the PP is up.
Artie
Edit: If you saw the comment about using a SPST switch, its wrong. :smack:
To do the above requires one more connection that's a bit harder to describe. I'll post a pic when I get home tonight. The pic is floating around somewhere buried back in a very old thread, but I don't know if I can find it now.