The most feature rich server for Matrix is the Matrix.org Foundation's own Synapse server.

You can read installation instructions here: https://github.com/matrix-org/synapse/blob/master/INSTALL.md

The basic steps for a Debian/Ubuntu machine are:

sudo apt-get install build-essential python3-dev libffi-dev python3-pip python3-setuptools sqlite3 libssl-dev virtualenv libjpeg-dev libxslt1-dev

sudo apt install -y lsb-release wget apt-transport-https
sudo wget -O /usr/share/keyrings/matrix-org-archive-keyring.gpg https://packages.matrix.org/debian/matrix-org-archive-keyring.gpg
echo "deb [signed-by=/usr/share/keyrings/matrix-org-archive-keyring.gpg] https://packages.matrix.org/debian/ $(lsb_release -cs) main" |
    sudo tee /etc/apt/sources.list.d/matrix-org.list
sudo apt update
sudo apt install matrix-synapse-py3

Then just edit your /etc/matrix-synapse/homeserver.yaml file and set your SSL certifcate, host name and port.