Thank you for contacting Intel.
On Windows* 8.1, I would suggest Intel® Ethernet Server Adapter I210-T1 as we have full driver support on Windows 8.1. Unlike the Intel Gigabit CT Desktop Adapter, we no longer provide driver updates. We do not commend on the pricing on third-party products. The parameters of these adapters may be the same but the HP's* adapter could be tested and customized for HP systems.
I hope this helps with your decision.