Mounting XXL prints

[gattu marrudu]

I knew I would hit this wall sooner or later... after pulling a series of 51"x78" prints (see (there was a url link here which no longer exists) and http://lii.cc/articles/view/146 ) I still have to mount them...
I have little experience in mounting photos and this looks like a quite complex job.
I am considering several options, balancing aesthetical, practical and economical sides:

• Aluminum: I'm not too keen on mounting fiber based prints on it, but such a size needs a really solid and archival base in order to look good.
• Gator board: sounds OK, but I don't know how archival it is. It is expensive, but I saw some interesting discounts on http://www.foamcoreheaven.com and http://www.artsupply.com . I never used it, but I think the minimum thickness for that size should be - 1 inch, 1.5, I guess? But the rigid part seem to be the outer layers, while the core is the same mushy stuff as foam core... so I don't know how much thickness matters. And I would have to support it with an aluminum frame on the back.
• Framing the sheet on a canvas frame. I know it sounds crazy but I love the aesthetics. It would be very hard to do, though, and I would need several scraps to try on. The sheet would have to be mounted wet and let stretch as is dries. A thousand things can go wrong.

Any suggestions?
gm

 

[wildbill]

gatorboard doesn't use the same core as foamcore, it also doesn't warp like foam core. 3/4 or 1" may work just fine.

 

[gattu marrudu]

Dibond board looks very nice. Does it come in 51x78" or larger sheets though?