>>364028170
Depends on what you currently have. Vive trackers are pretty good, I haven't heard anything about tundra yet.
You need at least 3 vive trackers for fullbody, and you also need 1-2 lighthouses (preferably at least 2). If you already have a Vive or Index, then you'll probably already have the lighthouses.
If you have a Rift, Rift S or Quest 1/2, you will have to use a hybrid tracking setup, which means you will need to buy separate lighthouses if you want to use the vive trackers. You will also need to calibrate every time by waving both the controller and the tracker around in the same hand, which is a pain in the ass.