Death Metal & tech stuff...

I posted this a few weeks ago, but reposting in "Tech Talk" to try to get some more input:

I'll try to use the appropriate audio terms. Metal (death, grindcore, technical, progressive.) 300 BPM double-bass kicks drums, trem-picked A-tuned baritone guitars, so I think I'm looking for good transient bass. On the high side, trash and china and splash cymbals, but I want to hear each flavor of cymbal. Don't have to be towers, may scale down and do bookshelf-size and sub. Do I just get some used B&Ws? Budget, maybe $500/pair used.

I'm also thinking I may just build my next speakers, so also looking for any general input on engineering. Kind of tired of horns. I'm thinking I may want a sealed system, but open to suggestions including enclosure types, (sealed, transmission line, arrays,) baffle arrangements (MTM/D'Appolito, time/phase allignment,) drivers (#, size, brands,) x-overs (type, order,) etc. Thanks!

If I were to test such a speaker to an extreme:

Nile, Krisiun, Dying Fetus, Cryptopsy, Meshuggah, Decapitated, Strapping Young Lad, Opeth, Morbid Angel.

My current system:

Klipsch RF-3s (w/ homemade 10 lb. crossovers)
Nakamichi (some model, CD transport)
Adcom GDA-600 DAC (auction for 100 bucks)
Alesis 31 band graphic EQ
NAD C-350 Integrated (but also playing w/ Yamaha AX-500 a friend gave me.)
I think the speakers are the weakest link. Don't know if I'm a fan of the horns either, not that they came with decent horns or anything. Placement is finicky as far as imaging goes. They're in a small bedroom, too small for horns I think, can be harsh, fatiguing. They were GREAT in a big living room w/ the huge center and surrounds w/ some DTS, but they're not working here. I'd like better midrange (a midrange driver might be nice) and cleaner detailed highs. Some type of studio monitors, some JBLs maybe.
In a small room monitors and a sub or two would be ideal. Go out and audition as many monitors as you can in your price range. Don't worry about the lower bass to much because the sub will handle that. If the bass is your number 1 priority I would spend as much as you can on subwoofers. Another thing to consider is that your horns are very efficient. If you change to a design that is less efficient then you will need more amplifier power also.

Happy hunting.
Don't know of anything in your budget that would meet your requirements but you might consider kits from GR Research or Raw Acoustics (site down temporarily).