As a Realtor, Mortgage Broker and Certified Mortgage Planning Specialist I would highly recommend your very first step be a Pre-Approval if you desire accuracy in knowing your total costs upfront. The type of financing you choose has an immediate effect on what your options are.
There is a difference between a Pre-Qualification and Pre-Approval. If you are looking for accuracy void of surprises you want to be Pre-Approved first. For the differences see: http://www.Steven-Anthony.com/default.aspx?pp=39377
Via the Pre-Approval process you will know exactly what you can "technically" afford based on current interest rates, Then, it's up to you to decide how comfortable you want your payment to be by reducing your target sales price or increasing your down payment. MOST IMPORTANTLY, the Pre-Approval makes you aware of any issues that will prevent you from buying when you want to.
As part of the Pre-Approval you should also ask for a Good Faith Estimate if you want to know all of the costs of purchasing a home based on a set Sales Price that includes all third party costs (title, escrow, insurance, property tax, appraisal, inspections, etc.).
My suggestion on financing would be a 3.5% down FHA loan due to its forgiving credit flexibility.
Any further financing questions let me know.
Good luck to you.
My advice is to find a lender who can get you fully pre-approved before shopping for homes. The advantage is you'll know for certain what you can afford, and when you write an offer, you'll look like a credible buyer and sooner or later your offer will be accepted.
I know you really want to get out of Whittier. If you need a referal to a lender, or simply have additional questions, you can reach me at (213) 598-5224.