Glenn -
You have said many times that this year was going to be the hardest year yet to book, and it seems that it's just gotten harder. I don't envy your position.
That being said, I would think that your replacement headliner should be one that draws as well as Nevermore would. When it comes right down to it, *any* of the bands you outlined above would draw as well as Nevermore. Sure there will be some people that say "I love Nevermore, but hate band X", but there will be just as many saying the opposite, I may be one of them
It doesn't seem like it's in your best interest to go after a "gamble", this is a business and you need to have a solid band that will bring poeple in to the festival.
A question I have - how much does one headliner influence the ticket sales to the festival? I personally have only been really excited about one headliner in the history of the festival and they stunk once I saw them.
I think with the solid line up for the other nine bands as long as the last band is "headliner" quality there won't be any problems. I think for the financial health of the festival, a safe choice would be best. If it doesn't make sell-out time records this year, but still sells out, I would think you made the best decision.
From my personal standpoint, I'd love to see a previous number three or four band that was great get the opportunity to headline. But I think that's because in the past, it's been the 2-4 slots that interest me the most. Supposedly Crimson Glory is going to play Euro fests, they'd be a great one as well. So would a John Arch set. Other than those two, I can't think of any 80s/90s reunions that would be headliner worthy. Honestly, would a reunion band draw more than Symphony X? Would they be cheaper?
So, bottom line, I'd say the safe route makes the most sense... i.e. the cheapest "headliner" quality band, that you know has and will draw fans.
Oh, and please no more Angra