the easiest ramp would probably be kymeegah(cooks river) as kings like structure try along the wall at mol pt, all of the markers in the bay, drums, hot water outlet, fish farm etc etc
yakkas should be easy berley hard with bread/pellets in yarra bay the yakkas and cowanyoung will come to you.
As for what depths to fish it depends on where the fish are. I normally do a trial run past where i want to downrig to get an idea of the water depth there, set 1 of my riggers deep ie 2/3rds down and the other in the top 1/3rd. Downrigging speed is normally just in gear and at idle.
hope this helps