I'm not sure how stone is sold up your way. Down here you can buy ungraded bulk local stone, which would have a lot of waste in your type project. Otherwise it's graded by type/thickness and stacked on pallets at about one ton per. They can give you an estimate of sq ft coverage based on how many layers they normally stack on a pallet x pallet size.

Hand gathered stone is irregular in shape and size and works well for informal design. Quarried stone varies some in thickness but is cut to uniform rectangles.

I would be interested what your final choice is and cost compared to what we see down here (Arkansas). See the link below for a stone dealer not too far from me.

Here is a link that might be useful: Arkansas stone

Will they allow you to buy per piece? If so, I suggest using the thicker and larger flagstone for steppingstones, especially if they are not going to be placed on a mortered bed or concrete base. Thinner flagstone will crack easier. Layout your walkway with chalk or landscape paint and count how many you stones you will need.

Shirley

www.EdenMakersBlog.com

Here is a link that might be useful: Shirley's web site