I just did this a month ago and it's 100% worth it. Here's the hose I got:

https://www.amazon.com/gp/aw/d/B0B71HJRTW?psc=1&ref=ppx_pop_mob_b_asin_title

All you'll need is a tank. You can get the tank wherever. While there are places that may fill your tank, exchanges seem to be the norm (I'm in DC). It's like $25ish to fill my 5lb tank. It's really that easy. Just make sure you have a wrench to tighten the hose to your tank!

You can get adapters for the newer models just as easily, just make sure you get the right adapter for your model.

https://www.amazon.com/Vavoger-Upgraded-Soda-Terra-Connector/dp/B0B71HJRTW

This is for normal https://www.amazon.com/Upgraded-Machine-Adapter-CGA320-Pressure/dp/B0B7N613T6/ref=sr_1_1_sspa?keywords=sodastream+adapter&qid=1674797256&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyOVEwNlNBTUdRNlAyJmVuY3J5cHRlZElkPUEwNzM4NDU1M05TMzE1REZQTjYwTiZlbmNyeXB0ZWRBZElkPUEwODc5MDgyMzNINUk1SkJETkFEWCZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

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This is for Terra https://www.amazon.com/Vavoger-Upgraded-Soda-Terra-Connector/dp/B0B71HJRTW/ref=asc_df_B0B71HJRTW/?tag=hyprod-20&linkCode=df0&hvadid=598365509516&hvpos=&hvnetw=g&hvrand=4946787636406021793&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1016334&hvtargid=pla-1878852588231&th=1