Hesco has the best offerings out there now in my opnion and is the OE manufacture for most other companies. Velocity Systems is always another good source as an alternative. I highly recommend you talk to Mike at AT Armor he is a dealer for Hesco and can get you LE agency quotes etc.
https://store.atarmor.com/
I really like the following too models of plates (pick one based off thickness 1" thick is ok go 3810 III+ or if you need it to be thinner for visibility U210) They have some other cheaper heavier options with good protection as well.
Thickness - .98 inches
7.62x63mm-JSP: 2780 ft/s
7.62x54R-LPS: 2300 ft/s
7.62x54R-L: 2840 ft/s
7.62x51mm-M80: 2780 ft/s
7.62x39mm-Mild Steel Core: 2380 ft/s
7.62x39mm-Ball: 2380 ft/s
5.56x45mm-M855/SS109: 3117 ft/s
5.56x45mm-M193: 3150 ft/s
U210
Thickness - .5 inch
7.62x39mm-API: 2390 ft/s
5.56x45mm-M193: 3150 ft/s
5.56x45mm-M855: 3150 ft/s
7.62x39mm-M67: 2390 ft/s
7.62x39mm-M43: 2390 ft/s