SlientKnight is a very good app. I use Little Snitch as well.Here are some suggestions:
Level 1 (foundation)
Level 2 (good to have if you don't mind the convenience vs. security tradeoffs)
- Anti-virus (I use Sophos)
- Anti-malware (I use Malwarebytes)
- Firefox browser with ad blocking and Javascript blocking add-ons (I use AdBlock Plus and NoScript) for general web browsing. I keep Safari relatively stock and only use it with a very small number of trusted websites.
- Little Snitch (monitor outgoing Internet connections, essentially a reverse firewall)
- RansomWhere (anti-ransomware monitor)
- SilentKnight (utility for easily checking Apple's own security measures in macOS for updates)