Network setup?

[Techstyle]

You are correct, use the faster card on the internal network. Your ISP will be the bottleneck on the external network

[JaseP]

My recommendation is to buy a good PCIe network card for the internal network. My core (still running as a core/hybrid for now) forgoes using its sole PCIe slot for anything other device (video), and instead uses it for an Intel PCIe network card.

Good but not necessarily "great," by the way... a $30 card should be more than fine.