I'd be thinking that Liberalism is not in the cards at this stage. There are 7 known civs with paper and 6 with philosophy while you have neither. Could be possible to trade quickly for some of that, but I would not put much faith in that.
My thoughts would be to go for Guilds and perhaps look to knights. Then try to take the tech tree through Econ and see if you can get the free Merchant involved. If you'd like, it might be nice to save him for Sid's if you decide to get to Medicine.
With knights, I think a focused strike on the two closest cities of Justinian would get you the two extra cities you need and basically take him out of serious contention. Plus, you'd get a city with Buddhism in it for some extra flexibility. Best to do so before he gets guilds himself and has Cataphracts running about.
Hopefully by taking this route you can backfill the other techs with trades and get the better culture civics and such up and running later.