Well, you know how to get in touch with me, and he's free to email me. But in general a good combinatio of hardware would be a Radeon HD 6450 or Radeon R5 230 on the graphics side, and a Realtek 8168/8169/8111/whichever on the network side.

The two Radeons are basically the same card, just rebranded. Both passively cooled (yay) and both available brand new from stores for 40-50 euro.

Unfortunately for the Realtek card, there's a hundred different variants of this card, and I can't guarantee that they'll all work. However, if he does manage to get hold of a card that doesn't work, then we can debug it remotely.