For such number of users I normally use 2 CCR-1036, One of them does NAT and the other PPPoE.
You can go with PC based MikroTik install and use NIC like these. They are MikroTik barebone install compatible.
https://etronic.al/sq/dione-networks/txa071.html?
https://etronic.al/sq/dione-networks/dn078-network-card.html?