You can get some decent enterprise hardware for fairly cheap on places like amazon. I got a dell R710 for around $800 a couple of years back. The equipment tends to be a little scuffed up and older in terms of hardware, but they still offer plently of performance IMO. The one I have has a 6 drive RAID with 1.5TB disks, dual 6-core processors, and 128GB of ram. Only downside I would say is they tend to use quite a bit of power (around 207W from what I’ve measured).

Element and fluffy chat are probably the best options currently for android. I personally use Element as it reminds me of discord.