Any workaround and which equipment to buy ?
Firstly, a love of tinkering and a workable knowledge of linux is a must.
Minimal setup
Equipment
1. A Raspberry Pi (a model 3 is almost good enough as a desktop system) and case
2. SD card and maybe a SFF USB drive
3. Power supply (mobile phone portable chargers work well)
4. Wifi dongle (or mobile broadboad dongle, though you could tether your phone too)
5. OS for the raspberry pi - i prefer Ubuntu Mate.
6. Portable router (optional: i use a TP-Link TL-MR3020 flashed with OpenWRT)
On your Pi:
1. Install OS (flash the ISO to SD card - you need a computer to do this)
2. Enable SSH
2a. Optionally configure your Pi to login automatically to the CLI or UI
3. Install and set up Transmission CLI (has a nice web interface)
On your iPad
1. Install a terminal (Panic's Prompt is great)
2. Log in over SSH
3. With Safari on your iPad, go to the Pi's IP Address: i.e 192.168.1.2:9091 to access Transmission's web client
4. Torrent away! You can paste in Magnet and direct links to a torrent file.
Optional extras
1. Install a VNC or RDP server on your Pi
2. Install a remote desktop client on your iPad
3. Create a wifi network using the portable router
4. Use your iPad as a remote desktop for your Pi
Playing content
Assuming you are downloading playable (video, audio) content (and it's iOS friendly) you can use the Pi as a web, webdav or DLNA server and feed your content to your ipad that way.
If it's documents they can also be transferred over HTTP. If they are ePubs, you have the added possibility of installing Calibre, an ebook management tool with a built in server.
Alternative scenario:
You can pretty much do the same set up on a VPS like AWS or DigitalOcean if you don't want the hassle of buying and setting up the hardware. Even remote desktop works well on a good broadband connection. The flip side means you need to be online to access your rig though. I can get you $10 credit for DigitalOcean if you like
Another alternative that's more out-of-the-box, would be buying an Intel Compute Stick or a
Kangaroo. The Kangaroo looks really compelling but it's not available in Australia so I'm SOL and besides, I do like to tinker