Palmetto Point was one complex that came to mind when I saw your first message. We had a friend who looked there and they were very nice and the area is pretty safe.
Don't know much about River Landing other than it looks nice from the nearby bridge I drive over.
However, neither is very convenient to shopping, etc. Walking would be difficult and bus service is very spotty. There is a bus that goes close to River Landing. I did not find a route near Palmetto Point. Click here for more:
Coast RTA
Getting around MB depending on bus service is difficult. You would need to study the bus routes and find a complex near the bus routes.