Hello,
First of all thank you for this opportunity. I work as a Project Manager and System Administrator for Linux and Windows Servers.
I have a 7+ year experience with cPanel and especially WHM, since I manage multiple servers and accounts.
Most of the tasks you require, are already integrated in cPanel. For the spam and backups, I will train you and we will also edit together some parameters to tune them for your requirements. Please understand that every server and every person needs some specific requirements to be tuned. We will use the best practices to do this but we will adapt them to your situation together.
1) The backups can be done locally and remotely. Ideally I would suggest you a remote backup server, but in case you can't, then locally would be our only option.
2) About the SPAM, you already have the best tool installed that is SpamAssassin. We are going to tweak and tune it to check the SPAM score better and compare to blacklists too.
3) For malware scanning, in my bid, you have included 2 tools. One of them is free, another is commercial (one time payment). This tools will make your server absolutely bulletproof and hacker free. The commercial tool has a real time scanning that puts suspicious files automatically in quarantine when those files are uploaded. We will also set in place, iptables and other security measures.
I really hope to work with you on this. I know that my bid might be higher than the others but it has a real value.
Regards,
Francesco