#3
peavey xxx is what most metal bands use. that and the mesa tripple rec...but those are a little more expensive.
#5
I'll run off a list:
Mesa Recto
Mesa F series
Mesa Mk. series
Peavey 5150/6505
Peavey 5150II/6505+ (better cleans because of extra pre-amp tube)
Peavey Triple XXX
Peavey JSX
Marshall JCM900/JCM800(It can be pushed to play hardore)/JCM2000
Marshall Plexis (Yes, they can pull off hardcore. UnderOATH or The Jonbenet, anyone?)
Orange Rockerverb series
Orange AD series
Any ENGL
Framus Cobra
Framus Dragon
Any Soldano
Any Krank (Too bad they suck.)
Any GOOD Randall

Do some more research. I'm not listing every high gain amp there is.
2005 Epiphone Les Paul Custom
Marshall JCM900 MKIII Master Volume head
Carvin G412T cabinet
Line 6 DL-4
Boss BF-3
Boss CS-3
Boss NS-2
Boss OD-20
Boss PH-2
Ibanez TS-7 (being modded soon!)
#6
most randalls actually are good... pretty much all their "bigger" amps are decent sounding. you might wanna rule out the 5150 and a couple others... don't metalcore bands have "breakdowns" with nice cleans?... from what ive heard 5150's dont have nice cleans... so check out the 5150 II? nicer cleans?... hm... giver
#7
I know none of the 5150/6505 series is known for cleans, but it'd be good to have the 5150II/6505+ just incase, since it has seperate EQ for both channels and an extra tube for the cleans. IMO, the best amp to get would be an ENGL Powerball.
2005 Epiphone Les Paul Custom
Marshall JCM900 MKIII Master Volume head
Carvin G412T cabinet
Line 6 DL-4
Boss BF-3
Boss CS-3
Boss NS-2
Boss OD-20
Boss PH-2
Ibanez TS-7 (being modded soon!)
#9
The DSL has lots of gain, but you might need an OD pedal to push it some more.
2005 Epiphone Les Paul Custom
Marshall JCM900 MKIII Master Volume head
Carvin G412T cabinet
Line 6 DL-4
Boss BF-3
Boss CS-3
Boss NS-2
Boss OD-20
Boss PH-2
Ibanez TS-7 (being modded soon!)