I would never do that if the goal is a private server people trust me to run. Good luck with it.

100 - 200 users is a lot, especially with public federation. I would go for Pleroma fork or setup Pixelfed as direct IG interface.

16gb recommended for people actually using it. It’ll be $40 - 80 a month VPS.

Since you plan to scale up, go 16gb minimum. 100gb minimum, but consider how you want to handle photos.

Looks like a great tool for integrating with searxng