For a small finishing compressor I'd look at Oil-free compressors having direct-drive design with no belts & parts to adjust.
Most people have 120-volt standard household current available. If this is the case, then a 6-HP compressor will be the largest unit you can operate.
Certain tools require a higher volume of air and higher air pressure than others. There may be times that you would like to operate more than one tool at the same time. Match an accessory's air consumption and pressure specifications to that of the compressor.
Most air tools, like the 3/8-in. air drill or 1/2-in. impact wrench, run intermittently, which allows the motor to catch up with the air usage. Smaller compressors can handle these situations. However, other tools run continuously, requiring more air than a smaller compressor can deliver. A larger capacity, more powerful compressor is needed to supply continuous power.
That said I Bought the Craftsman (By *****) 150 psi Compact Air Compressor
It delivers 150 psi max. pressure, 2.0 scfm at 90 psi. 1.5 gal. pancake tank provides low center of gravity. Quietly operates at 79dBA
I use that mainly in my shop & when I do crown / finishing jobs.. extremly light and quiet... and it's only 99 bucks, unbelievable huh?
For my framing crew & running 2 guns and much heavier work (It's noisy & heavy but powerful) Job Boss™ 4.5 Gallon 150 PSI Portable Air Compressor, it has a removable guage control panel so you can have it where you are working, plus excellent wheels & power... but it will blow a 15 amp breaker when it cycles up on a cold morning.
An excellent buy for me, I'm extremly happy with it... I love the new technology where it, runs very rarely and brings it up to cfm really quick in noraml use.
Here is a link for an image & specs
It's specs are:
1.6 HP (running) 4.5 gallon, mobile, contractor-style, single tank air compressor.
120 Volts/60 Hertz/1 Phase.
2-port removable console to allow remote air regulation and higher air pressure closer to the job site.
Full roll cage frame for pump and motor protection.
4.5 gallon storage capacity air tank supports heavy use of brad nailers, staplers, and finish/roofing/framing nailers.
Large, easy-to-read regulated air pressure gauge.
Mobility kit for increased portability on the job site.
Oil-free pump design for durability and no maintenance.
150 PSI tank pressure for longer tool run time.
Air delivery 7.7 SCFM @ 40 PSI, 6.0 SCFM @ 90 PSI.
Higher 120 PSI cut-in pressure provides 30 PSI of bonus air before a 90 PSI rated air tool becomes inoperable.
Two-pole, 3450 RPM capacitor start induction motor for maximum air delivery.
High-flo air regulator and push-to-connect couplers.
15 Amp current required.
Standard Equipment: 3.5 HP, 4.5 gallon, mobile, contractor-style, single tank air compressor with mobility kit and ASME safety valve.
Alter Eagle Construction & Design