Vaeris Rune. He's rarely been one for pets but given that he is entirely alone and hates people he would be interested in having something to talk to. He's a paranoid individual and would probably support something that would either guard him (since he's weak right now) or would act as a lookout of some kind. Suggestions are the following:
Ysalamir. He's paranoid and is willing to take the risk of not being able to use the Force if it means others suffer the same disability. (Unsure if canon, but they're cool.)
Vornskr. Due to them hunting using the Force one of these would definitely help protect him against other Force users if he could train it. (I'm not sure if canon or not though.)
Arrak Snake. He thinks they're cool and it's musical call could alert him to the presence of other people, because he hates people.
Krayt Dragon. He thinks they're fascinating and has always wanted one, but beyond that doesn't have an actual reason for wanting one.