Everything you said made sense until the High on Fire remark. They aren't even on the same label because HOF is on Relapse Records.
Now they are, but when they were on tour with Opeth Relapse had them."KOCH Records announces the addition of critically-acclaimed heavy trio HIGH ON FIRE to its roster. The band just completed a run of West Coast dates and now will focus on writing the new CD that will be released in Summer 2009."
you were both wrong
i think Opeth should open for Opeth
Actually, get Dream Theater there. And let them play a full-lenght gig.
Best choice!
In fact a better thing would be they would be playing singing for each other's songs. (Mikael would sound so nice on a Dream Theater song, for me their only weakness is their singer..)
Earthless
Eternal Tears of Sorrow
OR..
Bands that make up their style of music.
Morbid Angel
Camel
Etc...