I put a passively cooled GT1030 in mine and its doing the decoding & tensorrt detection for 4x 1080p cameras just fine, based on its current load I expect I could add another 4.

I couldn’t tell you if that specific Amcrest camera will work, but I have 2 of the recommended ones on the frigate docs (https://www.amazon.com/gp/product/B083G9KT4C/) and they work.

I self-host a bunch of stuff and don’t bother paying for a static IP.

I just have a cron job running that checks my IP and then uses API calls to update my DNS settings. I’ve got the DNS setup with Zonomi which are a local company, it costs maybe a couple dollars a month & i’ve got 8-10 domains running at any one time.