Earlier I posted a thread about modding a Precision bass.

It started out as a basically stock American Vintage Series 1957 Precision bass. I say basically stock because I replaced one of the tone pots two weeks after I purchased the bass (it broke:hmm:)

So now I'm upgrading it so it gets more play time almost on par with my Pino Palladino bass.

Aside from hardware upgrades (brass bridge, Hipshot bass extender, etc) I've decided to add some stuff electronically.

I'm keeping the Precision pickups on but I'm tossing a DiMarzio Model One in the neck position. I'm not going to be doing the electronic work myself (having a friend do it for me) but I need some advice.

+Control layout- Since I'm using the original pickguard should I the knob configuration volume/volume/tone and route a hole in the side. Or something different?

+Stacked knobs- I'm not positive what these are but if I can combine two volume knobs (or two tone) without drilling a massive hole in the side of my bass, I'm happy. Can someone clue me in as to what these really are, I'm lost...

+Best pots- What do you folks think are the best ones? Are my stock fenders fine?

So, you're adding a pickup to it?
If it were mine, I would use the dual concentric (stacked knob) configuration to preserve the pickguard in it's original state.
Basically, each knob has an upper and a lower knob. The original jazz bass used this. Upper knob=volume, lower knob=tone. So you will have a vol and tone for each pickup.

Go to bayoucables.com and order a wiring harness from Butch.
http://www.bayoucables.com/store/catalog/-c-34.html?osCsid=2f6fba56e19242c535946d56025d34dd

Just email him and tell him what you have and he'll email you back with a quote. Usually fast work and uses only top quality parts. Makes it a breeze to hook up, you don't even need to solder.