NEVER use PVC for air. OSHA forbids it, and there documented cases of explosions. I don't know whether it gets cold and brittle, or hot and stretches. But when it ruptures it generates flying, sharp debris that can injure people.
So far as the compressor
I'd stay away from anything Horrid Freight
Get a belt drive, if possible an all cast iron pump and in NO case settle for an oiless or direct drive
Forget about tank capacity, unless you simply cannot afford a large enough pump
Take the largest tool you figure on using such as an air sander, determine the air flow requirements, and go from there.
Be careful of "claimed" air output, amperage and horse power
REAL horsepower of years past was rated as motor shaft HP
FAKE hp is derived from the amperage it draws, and is theoretical, sometimes just plain untrue, and depends on the motor efficiency
Airflow: There are three popular ways of rating airflow, only one of which is "correct"
Airflow at (typically) 90 psi. This is the ONLY way to rate airflow, as it reflects what the tools are using
Airflow at 40 psi. This makes a smaller compressor seem larger, as any pump moves more air at lower pressure
Airflow at SCFM. This is INTAKE IE atmospheric air, and is a total fake, and makes a REALLY small compressor seem REALLY big.
Take all ratings with a grain of salt.
If you see to 2hp units with vastly different ratings, the larger one is probably an "optimistic" figure.
