Thanks so very, very much, everyone, for all your replies (not to mention all your help and great advisement all along)! I'm deep, deep in thought at the moment -- I got my ISBN number just yesterday, and much to my great surprise I got my CIP data today. Only thing holding me back is waiting for my application with Apple to go through (already in the works) and... well, REALLY making sure that I'm REALLY happy with my ebook, of course.
And that's the hard part!
I'm thinking... really, really thinking. I'll get back to y'all with a better response (on your other replies) tomorrow or something, but in the meantime I just wanted to say thanks, so much, once again!
Back to my thinking cap (and what's going on underneath it)...