In the last 90 days, 1 listings have been made available, which means listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 300% of the listings in the Oyster Bay 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 posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 900 sqft. Most properties in this market are around 3 floors. Most buildings in this region were built in 1945 and are Class A.