Concrete paver manufacturers around Los Angeles CA?
Try either ORCO and Angelus Block.
They will sell to the public, but like all manufacturers, they will probably not be cheaper than their real customers because of volume. - A manufacturer of a high volume product does not dare to uncut a customer on price. Many manufacturers do not want to deal with individuals because of the time involved.
For just a patio, a 60 mm (2 3/8") thick paver should be adequate, although 80 mm units are available for driveways, streets, etc.
Both of the manufacturers have good sites showing many different colors, patterns and application ideas.