diving shop if you have one in in the area but those are only going to be likely under 3000 psi. there is a tme period for tanks_ expiration date_ I think 10 years from oem mfg date and then no one will fill them any more. They also have to be pressure tested every so often and there is a charge for that- used to about $50 around here. In the early days of PCP units that was fine as most units ran at about a max of 2700 psi, now days units are bouncing of the 4000psi mark and a few higher with at least one so far at 7000psi. New tanks for pcp can do 4500 psi most dive shops and fire stations do not fill that high a psi. For he cost of a new 80cf tank you can get a GSX pump, the #4 is an 12v unit with adapter external for 110 v. the 4I has the power supply built in , at the moment I can remember if it will run on 12v also. around $600
