Or... you could tank it yourself.
DRG/SAM, he doesn't hit hard at all. Furthermore, if you have Atma of Roaring Laughter or even Atma of the Gnarled Horn, you could manage quite well. All other Atma's can remain the same: VV + RR, and or VV + RR + Apoc, whichever you prefer. I myself have done this with VV + RR + Apoc.
Honestly though... it's such a long task to gather 50 of those things, best to just have a small group of friends along for the ride. A good WHM, a THF, and 2-3 DD is all you really need. Holy Waters are also a nice bonus to have. But anyways, any well geared smart DD can tank this with appropriate Atma's, and Abyssite by no means are you in danger of tanking on DRG, WAR, DRK or whichever it may be.
*You also have a large assortment of temp items, Doom Screen, Fanatic's Powder are some that are worthwhile for this fight.
*If you're really desperate to solo this, you could always brew it. If you have Shinryu's stuff... you could always just go nuts by yourself... literally...