Help choosing a Chinese name among a few shortlisted ones
Any answer would be very subjective 

In my opinion, 孙博良 is the best choice. Not only it sounds similar to  Paulo, the characters also are common in native Chinese names and with positive meanings.

「博」 as in 「知識淵博」(widely knowledgeable), 「博學多才」 (knowledgeable and talented)

「良」 as in 「善良」(kind-hearted), 「良好」 (good; fine)

When people ask you how your name is written, you can quote: 「博學的博, 善良的良」

Most importantly, this name has 書生氣 (sounds like a scholar's name)