With school aged children, Carmel and PG are your off-base choices. Outside of that, the peninsula is not a very good area for families unless you are one of the rich doctors/lawyers that populate the million dollar homes tucked away in the mountains somewhere and send their children to private school. Professors have told me that they are nonplussed with the school system here in general. If you are still a LT, both areas are substantially higher than BAH for a decent rental, with Carmel running up to $3500-4000/mo. PG is $3000-3500/mo for a decent place with a lot of 'traps' going for $2750-2950 (2012's O-3 BAH, which has been lowered. Hopefully the rental market has adjusted by now, though). There's a thick fog that regularly rolls into PG because you're on top of a mountain. The houses tend to be built for year-round temperate climate complete with thin insulation and single-pane windows, so if you (or your wife) can't tolerate the inside of your house being mid 60's then the fog can drive up your heating bill substantially. Just something to be aware of. If you don't mind wearing a sweater indoors in July then go for it.
La Mesa offers 1200-1300 sq ft ranches/duplexes for O-3, if you can even snag one. The O-4 section has bigger units but many are still duplexes, if that matters to you. Base housing on La Mesa is smaller and more expensive per sq ft than some of the places in Monterey/PG/Seaside, but you know that the community is good, your utilities are included in the rent, and you have access to a fitness facility and CDC right there. With school aged children it's a much more sensible choice if a unit is available there since the better bargains aren't always in the areas with good schools.
La Mesa is first-come, first-serve and will reserve a place up to 14 days in advance before you have to start paying rent to keep it.
Seaside had 22 shootings in 2012, mostly gang related, and Salinas is worse. There is also practically a new guy being arrested for child molestation everyday Salinas. I don't recommend bringing school-aged children to either neighborhood.