The kinect v2 costs way more but has better fov, more bones to track, fixes the hip issue by making it a straight line. This allows you to fully crouch and sit down. The kinect v1 on the other hand has a small fov and small resolution but it costs way cheaper and if you bought a xbox 360 in the past you might still have a dusty one around.
The adapter is the disgusting part of the kinect v2. It costs £40 for the adaptor alone not including a £110 kinect v2. The kinect v1 is £30 and the adapter is £10.
I currently use the kinect v1 and it has OK body tracking but not as good as the kinect v2’s.
Also i have noticed if you have a big play area and you put the kinect v1 far way the kinect v1 tracking goes janky as the resolution is only 480p compared to the 1080p camera the kinect v2 has. I have also found that the kinect v2 has way less frame drops than the kinect v1 and consistently keeps around 30fps.
In conclusion i think that the kinect v2 is way better but i would suggest trying to see if your kinect v1 works.