Andy
I did find a DeGaris family but they were not of the names you gave. No Hamon families what so ever Im afraid 
Are you 100% sure they went to South Australia?
Shanko
Shanko,
Thanks for checking that for me. Yes I am 99% sure they all emigrated to South Australia, as there is death records of all but Julia in Adeliade, and it is also known that Julia married someone from Adelaide!
I actually just thought of another couple of things that would be great if you could look up for me:
Death record of Julia DE GARIS (or possibly KING) DOB 26/10/1837 in Guernsey
Marriage record of Julia DE GARIS to AARON KING (of Adelaide)
and this one is a bit of a long shot but:
Death record of Joseph Garibaldi MOLD born 1862 in Walsall, Staffordshire, UK.
He married Emily Helen HAMON on 23/1/1890 in Adelaide and left her shortly after their daughter was born in 1891. Apparently he was a gambler among other things, but no one knows what happened to him. Also if you can think of any other types of records I could search for him, could you please let me know?
Thanks very much, I know that might have been a big ask.
Andy