From the information I have on Peter Coffee, there does not seem to be an connection. Hiram first appeared as a 19-20 year old in 1819 when applying for a marriage license. In 1850 the census record stares he is 50 years old and his BP as TN. So far I have not found any siblings or parents prior to 1819. Although other researchers have tried to fit him into other Coffee/ey lines, the proof is not there.