You should really get yourself prequalified so that you know what you will be able to afford. Otherwise you may be wasting money on mailers, and waisting yours and the Seller's time haggling over a deal. Besides having a pre-qual in hand is a good negotiating point.
Buying units for your first property is a fabulous idea and taking advantage of the FHA super low down is a great way to buy units
I would also take a look at what is listed on the MLS just in case you see a deal that you really want. SD is expensive and even off market deals can sometimes sell for almost as much as retail. I can run a search for you and email you the link if you want. My suggestion if you want to do mailers would be to go "driving for dollars" and look for some more rundown properties in an area that you want to buy in. Then you can get the owner name and address from the tax rolls and start your mailing. One hitch may be that the owners may not want to do any work, and some older buildings will not meet financing criteria so you may need to get a 203 qualification as well.
Regarding out of state investing, it is a good way to make some cash and high returns with a lower point of entry than San Diego. However, I would use that FHA loan and buy your first Owner Occupied Investment property with little down first and foremost. I currently own rentals out of state in Northwest Indiana. If I used my money to buy a home, I would be paying the same amount as my current rent, but have upside in appreciation, but risk in depreciation and repairs, liability, etc. If I bought a rental here in San Diego with my cash, I would be collecting about $1500 a month in rent. However, I am collecting $7400 a month in gross rent which pays my rent and then some. Food for thought.
Let me know if you want any help.