My Biarum tenuifolium is putting out foliage now and made it through it's first Z7 winter unscathed last year. I also have an Arum concinnatum that has put out leaves in January the last two years and bloomed in February/March.

Try Telos or Hillkeep for these.

Seneca Hill has a few different types of Arum as well.

Susan

Here is a link that might be useful: Seneca Hill

There is a Hardiness list on the Aroid website that may help. Keep in mind that the tubers may survive, but on some species, the foliage will often disappear after a hard freeze. They resprout new growth after the temperatures become more moderate. One that survives, along with A. italicum, is A. maculatum. It is the last one of my species to emerge in the fall(not up yet). It is also available with patterned leaves.
Rb

Here is a link that might be useful: Aroid Hardiness List