I'll let you do the research on max spar length comparison with the Passagemaker, but note that I'm able to fit everything (spars, mast, sail, tiller stick) for a lug-rigged NE Dory into one old mainsail bag for a Flying Scot.  Near perfect fit for both length and diameter.  With the sail wrapped in there there is next to no rubbing together of spars, if you're worried about that.

   I sewed one myself from some material we had on hand- some kind of fairly open weave synthetic that breathes and dries quickly. It has two long zippers that meet in middle so you can open up the full length.

Thanks for the replies