No matter what you will need to have a pre-qual letter as no one takes an offer without one. You also may run into having to get a pre-qual again from that specific bank if you are buying a foreclosure. Bank of America, Chase, AHMSI and Wells Fargo all require you to pre-qual through them in order to put an offer in on one of their bank owned properties. This is an important investment. Take your time, do a lot of research, stay well within your budget; look at the cost of repairs- materials have gone up considerably, sometimes it's best to spend a little more and get something in better condition. These prices will be here for a while so you have a good year perhaps two before this market starts to head up; plenty of time to prepare well for your purchase. Best of luck to you!
I can't say it enough, talk to a Loan Officer of the Bank or Mortgage Company of your choice. Talking doesn't mean you have to deal with that particular person and/or bank but it is a start, at least concerning what you can do and what steps to take.
When I started in the Real Estate industry 28 years ago, it was not uncommon for Realtors to pre-qualify their buyer themselves. Nowadays, I would not even attempt to do it, there are too many rules, regulations, constant changes, type of loans, etc.
We are all more specialized, let's leave the "Mortgage business" to the "Mortgage Pros". Don't do yourself an injustice by not following the right channels. Good luck.
(If you are leery about who to talk to, ask for recommendations from friends and family)