I live mid peninsula - meaning Belmont, and know the area around me pretty well after living here some 25+ years.
Foster city is pretty kid friendly and a bit cheaper, but be prepared for finding a place to be a challenge in general.
The commute to MV by car can be a nightmare depending on time of day, you may consider taking the train to MV and biking to the office.
Redwood city and Menlo park are also options, but neighborhoods in these areas area a lot like New York City, a block or two can be a HUGE difference in neighbors and whether or not you will feel comfortable.