Jeff,
At 50 lb/ cubic foot green, your 8"x8"x10' Hemlock should weight about 225 lb. In my White Pine project I found big differences in weight from one piece to another.
I found a peavy was all I needed to "transport" pieces (as large as 8"x10"x18') from one place to another. Lifting these large pieces up to my work surface worked well with the teeter/totter (4' apart) technique previously mentioned.
I planned my work surface to be the same height as my sills and thus, was able to move assembled bents into position for raising rolling on short pieces of PVC pipe.
I was lucky for the bent (~875 lb) raising in that there was a nicely positioned tree to which I attached a chain hoist.
I had a neighbor, who pointedly observed that a partially raised bent looked a lot like an oversized mouse trap, periodically stop by and lend a hand. But, I think it's clear that with time, patience, planning, care, a modest 18x24 barn can be built and raised single handed.
Carl
PS
I'm having trouble visualizing your "foundation".
Looking at your drawing, don't forget knee braces at the middle posts
