those can be wayyyyy different bass requirements, sir.
Cliff used Rickenbacker basses, often through massive fuzz and wah.
Slayer.... hmmm, Tom uses ESP these days, don't remember what he used in the old days... Kind of low-fi, more thumpy than crisp.
SOAD - no actual idea, but it's low (5-string required, or restring a 4 and tune it to C, B, or A depending on the tune - Aerials, for example is in C) - and is pretty hi-fi. Probably Warwick, maybe even higher-end Ibanez. Pure speculation here.
And Primus - whoo, well you can't mistake the burpy greasy midrange of the Carl Thompsons. I love his fretless tone myself. Harder to duplicate, especially since Carl Thompson basses are many many thousands of dollars and no two are exactly alike, but you can get mighty close sometimes. My fretless Warwick can "do" Claypool okay, it's my chops that have trouble =0).
But the point here is that all of these bands have a particular sound - If you can identify what *about* these artists' sounds you're after, it'll be easier to steer you in a direction. Also of note, each player imparts their own sound to the bass - you pick up a Ric, you won't sound just like Cliff, for example.
Just like always in here, I'll say go play every bass in every store close to you, that's in your price range. Something will jump out at you, or at least you'll like it more than others.
