It is possible and somebody will do it. I know for a fact there are already shops looking into resleeving the block with something along the lines of Darton MID sleeves. How rare 1000hp v6s will be remains a mystery, but i have no doubt that if Hyundai, Toyota, and Nissan 6bangers can be made to hold 1k, then somebody will do it on this platform.
Darton sleeves won't help as to survivability on this block. I've already said why. You could run all the big name parts you want and then the block will become the weakest link. Sonny Bryant, Oliver, Wiseco custom rotating assy will not save it as far as the original topic. Hardblok and a partial fill might help it last a little longer.
I'd talk to quite a few engine builders to get different points of view and feedback....even if you hear what you don't want to hear.