Feedback like yours makes it all worth it - very much appreciated! =)

That PC will net you a decent income, as it is very much near the top end of what hardware is available. Of course, every little bit helps so your small PCs and R-Pis will increase your yield somewhat. If you want to talk more about R-Pis, @scalextrix is your man.

I would love to learn more on how you do your research for which projects to pick.

There is a project in development that has not been released which gives real time yield statistics. I used to verify its accuracy, but now I just trust it's outputs blindly and it has never failed me. Expect a public release later this year.