i think, to fit your comfort zone, especially at first when everything is a bit confusing, you might be wise to focus on Discovery Bay. Lots of expats (you've mentioned that a few times so I guess it's a priority), family oriented, good value for size of flat, lots of options for schools (many HK Island International schools pick up at the ferry pier in central, or you can bus to others, and there is a new school coming in 2009), western food, close to airport, beach, lots of community activities, easy to get to Central/HK Island
look at the numbers Cara gave for an idea of rental prices.
Look at www.gohome.com.hk for more prices all over hong kong(though usually on the low side in relation to current prices)