go with the two stage operating at 175 psi it is the norm for industrial usage
i run my cnc's with those specs. it wont cycle as much during duty, if you plan
on using any air tools it will be alot more friendly. stay away from aluminum cly,
they just dont last. buy from a company that services them for industry. when
something goes wrong you get alot more mileage in getting it fixed.
Fred
http://www.origincorp.net/
heres the brand i have, mines 10hp 120 gal
http://www.gerardaircompressors.com/compair_kellogg.htm