Welcome to ATP, Tink.
A lot depends on the area where you live and if they will grow well there, but if you haven't found a source for sassafras near your area, you might try this link for Arbor Day trees:
http://www.arborday.org/shoppi...
Or Nature Hills which is an online nursery:
http://www.naturehills.com/sas...
I don't know much about the Mayhaw, but I'd look online again for places near you that might have it.
I know you're going to enjoy ATP.
