For the types of bands you like, I would suggest a Spector 5 Legend. They are 35 inch scale, which you will need when you downtune like a mofo. They have a cool signature growl and are built well. You might not even notice the difference between a Euro LX for example, which runs 1500+ from the Legend.
Spector Legends run about 800 new, but can be found for 4-500.
I upgraded mine and I would suggest you do the same. I bought 2 EMG 40DCX pickups and hooked them up with the EMG BQC preamp. It's an 18v system ideally so you will want to add a double battery box and the cavity will need some modding to fit the preamp in. This system comes to $350 all together I think. I also added a brass nut to add depth. Get the action super low, maybe even use a shim, and you are in business sir with a killer bass. It's one of the two basses I have that sound guys cream their jeans over. I was trying to make my cheap bass sound like Alex Webster's $4,000 bass. It worked well. I think my bass has more umpf than his does truly.
If you don't want to do any customizing, the supposed "winner" of the "Best Bass for Metal" joke was an Ibanez 405. I don't see why though. It's 34 inch scale, it looks very generic, it has limited tone shaping capabilities. I don't get it. I really am not a super fan of Ibanez tones. I've own several myself and played on some really high end ones. They have sort of sound the same to me, and the signature sound is not as impressive to my ears. Very flat sounding.
You will really need to just get your hands on several models of bass and see which neck feels the best for you. Good metal is all about speed and accuracy. Getting a bass that has a neck that is hard for you to travel around on will only set you back.
My best bass is a custom Carvin made from their "Bass Kit BK50A" and some carvin upgraded parts. It has 2 Jazz pups and 1 MM style humbucker that is a nordstram. Even in passive mode, which I normally hate, it is satisfying to play. Here's the specs for my custom bass.
Specs:
Scale: 34"
Spacing: 19mm
Body Wood: Walnut
Neck Wood: Walnut
Finish: Tung oil
Fredboard: Ebony
Frets: STRF - Stainless Steel Regular Frets .043" H .080" W
Pickups: 2 J99A pickups and 1 Nordstrand MM5.2
Preamp: Carvin 2 Band, 18V
Knobs: V(push/pull active/passive),V,V, t/b, mini-toggle for MM5.2 (series/parallel/single)