PSVR works with the original PS4 so you wouldn't have to get rid of the original PS4, and it's good enough to provide an immersive experience, but I do believe the Pro was created to improve PSVR.
Of course a PC and Vive will be a superior VR experience due to better fidelity, room scale etc. It's just Vive costs over $1,100 and if you don't have a capable PC that can be an additional $400 + depending on your current PC (graphic card, cpu) or more if you don't even have a PC.