In the last 90 days, 1 listings have been made available, which means leases most likley are going fast. You'll want to be prepared to make an offer immediately. About 100% of the listings in the Montecito are subleases, so you might be able to snag a great spot on a short term. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,900 sqft.