I would be interested in this also but in the reverse direction
#2 KazAussie has been a member since 18/7/2009. Posts: 221
Not that I know of -- most of the tours run Phnom Penh to Saigon via the Delta.
It's not all that difficult to do yourself -- boat to Chau Doc, overnight, then bus to Can Tho over night then bus to Rach Gia overnight and then boat to Phu Quoc Island.