Here's my 30 ton shop built press. I had design help here on RCM back
in 2012 when I built it.
http://www.mwdropbox.com/dropbox/shop_press.jpg

It uses a standard Enerpac 10,000 psi spring return cylinder with a
standard air over hydraulic pump.

I use the same 10,000 psi pump on my 30 ton enerpac puller
http://www.mwdropbox.com/dropbox/Puller01.jpg

ANYWAY, 10,000 psi is fine with proper equipment.

Karl