Poormans IN Van Buren CO Cass CO MI

Have much info on these Poormans going back to original emigrant,(abt 1735?) Hans George Poorman (Burman, probably b abt 1665 from Germany. Would like to find where he was from in Germany and other researchers who might have connections to Poormans in MI. John Andrew Poorman b 1844 d 1881 m Mary A. White. Have her father as Andrew, but need more info on this family. Henry Harper Poorman b 1816 Centre Co., PA m Martha Jane White b 1823 PA. have her father as Joseph (from her death certificate) but would like more info on this family. There is also a connection to Stones - John Andrew's son, Samuel Foster Poorman m Anna Mae Stone.