If you use the search function, type in the word compressor, you'll find dozens of discussions.

Given the work you describe actual air volume output and tank storage size is more critical than pressure, hp of the motor, or any other numbers game sellers of compressors utilize. As an example, I have a compressor that puts out 24 cfm at 90psi. It will fill the tank WHILE I'm using something like a da and not keep running constantly trying (in vain) to keep up.