Have you talked to a lender about what you'd be able to borrow, given your other mortgages? I have a couple I work with who have been helpful with making sure all rental income is properly accounted for, and that's important when you have to show you can make all those payments.
How much thought have you given to what kind of place you'd want to move to? Given your current PITI, if you move to Folsom or Roseville to something in the $400-500k range, you'll probably have a smaller house with a much smaller yard. If you want to stick with a great school district, I'd go with one of those areas.
If you rent, you might be able to come out ahead if you're willing to live in something modest. I've tried to build a financial model for buying a house to rent out in Folsom, and the numbers just don't work. It won't cashflow and even when I try to account for appreciation, it looks risky and it's easier to make money somewhere else. This suggests to me that renting is relatively affordable in these areas. Also, buying and selling is very expensive. Until you're certain you'll stay somewhere 4+ years, I recommend renting.
I'm an investor/realtor in the area and follow the buying and renting markets. If you'd like to discuss what's happening locally, let me know. I'm always interested to see what everyone else has going on and like to help where I can.