Newb when it comes to these subjects but really want to learn the hardware side of things - Help with old repository for EDTracker

Hello guys! While I am a relatively experienced programmer, I have practically zero experience on the hardware/electronics side of things. I really want and need (I'd like to work in embedded systems) to get this stuff in my "tool belt" of skills, but I am really worried that I will do something wrong or order the wrong parts because it is quite an old project I will be trying to build.

I would like to make this project (EDTracker github) so that i can play all my sim games that benefit from head tracking again. I had one which was pre-built but the connector broke. I would prefer a version with the magnetometer (9150 or 9250). The problem is that due to my inexperience I have no idea where to search for cheap(ish) components, or even if the components listed in the docs are still available or if there are better ones that do the same thing.

I realise this is not much (almost nothing) to go on, but I would really appreciate any help at all that can push me in the right direction. Also, please be understanding of my possibly ignorant questions. When you have no knowledge in a field it is often hard to know what the right questions are :)

Many thanks in advance!

Edit: Spelling