Compared to the rest of the Metropolitan Los Angeles market, the Fullerton submarket has lower rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 18 listings have come on the market, which means leases most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. About 6% of the office spaces in the Fullerton are subleases, so you will probably need to consider the implications of signing a direct lease with the building. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
Even though the median size is 3,250 sqft, there are still 0 new availabilities below 2,000 sqft. Most buildings in this area are approximately 2 floors. Most buildings in this area were built in 1975 and are Class B.