I honestly would not be worried about J or P as much as I would be worried about "is this a well made bass". Given the imperfect nature of mass manufacturing of consumer instruments, there tend to be more duds out there than gems. Give them all a try. Don't forget about other brands as well. I don't know if I have really run into a piece of music that truely demanded a P, or a J. Either model can fit, and most audiences wouldn't know the difference anyhow. Construction quality (frets, neck pocket, hardware, etc.) goes a long way to owning a nice bass, regardless of the cost or name. Sound quality once plugged in is highly important. Setup isn't as important, since that will change with time. It should just be important if it can[ be setup well. Very low on my list is color, and brand name. I have a Squier Jazz which outplays some boutique basses I have tried. Don't worry about cosmetics or names or even models. Ask yourself if it is well built, and if it plays well.