Have you considered a rear zip? The only reason I ask is that they don't have to be hard to get into. The reason I'm asking is that I originally shied away from rear zips because I'm not a contortionist, and hated the cord flopping around. If you have a long enough cord on the zipper, you can still quite easily zip it up yourself, adn then tuck in the cord so that it doesn't go all over the place. A front zip doesn't have these problems, but as there are less of them, you won't have as much of a choice. Regardless of what you choose, definitely take the other's advice and try a rental if you can.