Wow, I am excited. Poetry ebooks are hard!
You might find my post on the subject to be useful
Basically, the American Verse Project has high quality html versions of classic American poets
(but not Whitman, curiously enough).
You might find this Whitman archive resource to be useful
and especially this essay
I think PG uses the Deathbed edition, and some scholars say this is not the best or most interesting edition
This sort of TOC is a good reason why Sony reader needs table support (or some way to jump through a large number of hyperlinks).