In the last 90 days, 2 listings have been listed, which means listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 100% of the available leases in the Port Jefferson Station are subleases, so you might be able to sign a shorter term by taking over a previous lease. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around sqft. Most buildings in this region are close to 2 stories. Most buildings in this market were built in 1990 and are Class B.