I recently researched third-party services that do performance / uptime monitoring, alerting and more. There were a couple of good ones, but none that I found that integrated monitoring/performance/alerting along with a publicly accessible status-page/dashboard which also had the option to create incidents with status updates (text description). You might consider if this is worth adding.
For now I went with the Open Source Statping tool but I'd happily use an affordable service if it unified everything.
Hey! Sorry to hijack the thread for the other, but just like the OP we've spent the last few years building Oh Dear and it does about 99% of what you're looking for. [1]
It has uptime, performance, SSL alerts and status pages. What's missing is the performance graphs on the status page, which is coming in a few months.
Simple Ops goes further than us by also measuring FCP though.
For now I went with the Open Source Statping tool but I'd happily use an affordable service if it unified everything.