I think the best advice, is for Nomads to take a look at the area's mentioned, and see what area feels the most comfortable for him, and especially his family. His family will be the ones who will be living in the area most, and i cannot stress enough, how important it is to make sure the family is happy and content within the area chosen to live.
Sai Kung wouldnt be so popular amongst expat families with kids if it wasnt offering a lot more than many parts of HK, especially in terms of what you get for the $$$. The community there makes the area very enjoyable, having lived there ourselves for a few years, I can say that the commute time is not important. What is important is you enjoy living where you choose first, and adapt a fair and reasonable commute compromise regarding all the other lifestyle benefits.
It might be worthwhile to type the area's that have been mentioned into some online photo websites like Welcome to Flickr - Photo Sharing or PBase.com and get a visual feel for the area's geographic orientation.
Once Nomads is here on the ground, he can take a look first hand and get a feel for the location, and decide if its worth the commute, or not.
Thats about all I can really say regarding this. But I still maintain that Jade Villa's and Costa Bello offer the best rental property bang for buck in Sai Kung, if the budget is 35 - 45K per month inc car parking.
Both Villa estates have private swimming pools, Costa Bello also has right on the water front Sai Kung harbour views, you can literally fish from, and both estates have 24/7 security on site.