Marye, first off, WELCOME. Just looked at Biker's Friend. That would probably work successfully but I would suggest one large enough for your helmet storage needs. If you care to, go back to early 2007 in bike mods and look for a write up and pics of Lynda's GZ with a hard case/backrest combo. Half the price and not that hard to do with a little planning.
This little sweetheart went half way across Canada and back without a whimper. Lynda has since upgraded but will always have fond memories of her first bike.