Since I've never seen a Kyro 2 in action I couldn't tell you which will work better for you, but generally it seems that people with cards supporting D3D and OpenGL say that OpenGL looks better. As for the directX plugin you mentioned, that is a D3D plugin that Pete tweaked for DirectX 6. The plugin that says PeteD3D is tweaked for DirectX 7.
BTW, speed and quality differences between those plugins will differ from PC to PC so you'll have to try them both yourself to find the best. Also some games work a little better with one or the other.
[edit: added much needed punctuation]