Thanks I see now that the card he has pictured is an RTL8111 but I can't tell what the letter is after it. I looked for a specific model to be posted and I didn't find it. The RTL8111E on ebay does indeed seem cheaper. I'd like to just not waste my time and get something that I know someone else has working.
I recently managed to install MorphOS on my Quad G5 using a X1900XT and this exact network card, from this exact listing, so I can confirm this one 100% works: amazon link