Possibly most popular and best open source torrent client qBittorrent can be run on headless Linux (no monitor, no X available).
+ it has Web user interface (WebUI) built in. Setup was incredibly easy.

CentOS Linux: yum install epel-release;yum update;yum install qbittorrent-nox;qbittorrent-nox --webui-port=8080
Ubuntu(Debian?) Linux: sudo add-apt-repository ppa:qbittorrent-team/qbittorrent-stable;sudo apt update && sudo apt install qbittorrent-nox
This article mentions how to setup the service/auto-start on Ubuntu, but you may try possibly a bit easier way described below.

Daemon mode (task runs on background): add "-d" switch to the command

Run at Linux startup (tested on CentOS): echo "@reboot root qbittorrent-nox -d --webui-port=8080" > /etc/cron.d/qbt;chmod 600 /etc/cron.d/qbt
Cronjob can be also added to "crontab -e"

Normal GNU/Linux version for GUI computer with a screen: https://pkgs.org/download/qbittorrent

How to access downloaded content?
- Either download it to the destination via Torrent (possibly the best way)
- Setup FTP server