Portable single-stage compressors are popular with builders because they're easy to transport and provide a large air tank.
Gas vs Electric
When you're working indoors, you don't want the compressor running constantly.
And if you need to use the compressor in the basement and the second floor, you won't need to run hoses everywhere - just bring it with you.
Basically, where you'll be using your air compressor will dictate which kind to buy:
Gas-powered compressors cannot be used indoors because of dangerous carbon monoxide emissions. Due to the engines, they tend to be heavy and can be quite loud.
Gas compressors are good for framing and initial construction jobs - areas where electricity has yet to be installed. They are the most powerful option for portable single-stage compressors, cranking out a large supply of CFM.
Electric-powered compressors are good for remodeling and finishing projects because they can safely be used indoors. You'll need an electric source to plug into though.
These air compressors are quieter and lighter than their gas-powered counterparts so they'll be easier to transport.
Low Oil Shutoff
For a compressor pump to run smoothly and efficiently, it must be lubricated with oil. The oil also prevents the pump from overheating.
Look for a single-stage compressor with low oil shutoff, which prevents the pump from running when it is low or out of oil. This will prevent the internal parts from overheating and damaging the compressor pump.
All portable single-stage compressors are similar, but they're not the same. Cheaper models are equipped with small plastic tires. Look for a compressor with large, inflatable tires.
First, larger tires make the compressor easier to transport over rough terrain. Next, inflatable tires absorb vibration better and reduce rattling and make the compressor quieter.