Recommendation for customer monitoring network tool/portal for a large ISP

Hello, What solutions do you guys in the fixed network business/ISPs use to provide customer portals for network KPI reporting to customers in a fixed network on real time basis. The KPI in question are network availability, utilization, memory/cpu of managed routers/firewall, jitter, packet loss etc in a multi vendor environment. What would you recommend especially in the licensed/supported options and not the free ones like Zabbix, Cacti, MRTG etc. This solution should scale well for hundreds of thousand of clients. We have been using Orion NPM and it pretty much does the job but would wish to move to something more scalable for SP environment. Regards, Alex.