Lots of good suggestions. Here's an easy way to sort out compressors ...
- Budget. More is better
- CFM. More is better
- Space requirement - less is better (i.e. vertical tank or rotary screw pump)
- Motor rpm. Less is better
A small screw is a superb way to provide air for a small to medium sized shop. Figure a 5hp single phase unit will make 21 scfm @ 100psi & a 10hp single phase unit will double that. Eaton Compressor has both (and many more) in the $3600-$4500 range. I've spent many hours on the phone with Eaton's tech support & they are excellent.
A low rpm recip with pressure lubrication is another good option. The Quincy 351CS80VCB is a 5hp single phase unit, 80 gallons, that makes 18scfm @ 100psi. Pressure lubed units use an automotive style spin on filter so the pump always gets clean oil. $2700 at a number of online sellers.
A low rpm recip with splash lube is next. Splash lubed units use dippers or slingers on the bottom of the connecting rods to splash oil up on the cylinder walls. The oil gets filled with small metal particles so plan on frequent oil changes for maximum pump life. Quincy, IR, BelAire, etc. all make 80 gallon units for $1500-$2000.
$1400 buys a 5hp high rpm recip with splash lube & 60 gallon tank like the Quincy 2V41C60VC. $1300 buys the similar spec IR 2340L5-V
$1000 buys a 3hp high rpm recip, 60 gallon tank, like the BelAire 216V. NOTE --- Many manufacturers call this motor a 5hp but it's 5hp only if you still believe in Santa Claus. It's 3hp all day long & makes 15scfm @ 100psi.
Less than $1000 & you may want to shop Craigslist for a "gently used" :devil: machine that saw only home shop use.