Control users request in wisp

Hi, i have a big isp with 3 1000/1000 conventional fiber lines, mikrotik ccr1036 and 3 dell servers in a rack. i only use one of the servers for ubiquiti/huawei control programs for radios.

i wanna set up a proxy or something similar for control the websites and request of my clients if is necessary by spain authories.

i read a lot of squid and thundercache, but i dont know if this is the ideal por use with my mikrotik router.

All my network is on bridge, my only router is the CCR. I have pppoe authentication for all my clients with differents ip range, so im natting on my networks.

Thanks to all for the help.

Fran D.