USA Standard vs Special vs Highway One Precision Bass

[jimbojimbo]

Hi guys,

I'm looking to buy a new bass. Primarily I'm a guitarist, but with my job I play a lot of bass and need to get a decent one - I produce music.

Ideally, I'd like a USA P Bass, but the budget won't stretch to a new one, so I'm looking second hand and have around £500-£600 (max) to spend.

I've been doing some research but I'm still a little unsure of a few things. Would someone mind throwing me a few straight-forward bullet points, or something, to illustrate the difference between the types:

USA Standard / Special / Highway One.

I've seen a bunch around and getting confused as to what to do!
I'm not only looking for USA ones, I know they're the best, but I know that there are certainly some decent mex/Jap ones about, especially the reissues.

Of course, correct me/educate me where you can!!