I'm sorry.I don't have anything on your Horace or Phebe.(I have added them to my FTM data as unconnected, for the moment, just in case they can be connected up later.)
I was able to find the 1860 census record for them as living in Warren, Washington County, Vermont, with three sons: Gayland (6), Francis (4) and George (3).
Unfortunately, it isn't until you get to the 1860 census that they started listing all the family members.Prior census records just list head of household and enumerate the number of people in different age groups.
If you are a member of Ancestry.com (a very useful site for genealogical research), I found one posted tree with the correct family (http://trees.ancestry.com/pt/person.aspx?pid=-2092809322&tid=346340).
It doesn't list either of the parents, but the tree owner might know.If you click on the 'owner' name near the top, it will bring you to a page that you can contact the tree author from.
Another tree (http://awtc.ancestry.com/cgi-bin/igm.cgi?op=GET&db=:2683948&id=I1964) lists Horace with the right year, but the parents are from New Hampshire.
Good luck with your searching.I've been at it for about 8 years now and only in the past month was able to make the Antoine Paulin connection on my mother's father's side.