We found this CP an excellent base for checking out Mornington Peninsula and the Dandenong Ranges.
We'd been told Dandenong was not a nice place to stay, but we had no problems.
http://www.big4dtp.com.au/
Also check out the Dandenong markets, Tuesdays, Fridays and Saturdays. Everything you could possibly want is there.
Beth, now living on the Redcliffe Peninsula, SEQ.