Byzantium has a lot of fronts, are strong fairly early, and has a pretty strong and flexible roster up until gun powder. You can set up a nice frontier on the three or so rivercrossings to the north and west of Sofia if you want to expand that far. Perhaps if you leave Anatolia (if that's the correct name for modern day Turkey) and stay in Greece it might be interesting.

I find it a test to my patience playing like that, I've often planned to do it, but then wonderful opportunities arise that I cannot refrain from taking advantage of. I also want to keep my generals busy and skilled, which leaves little room for peace or waiting for the AI to come to you, at least in oh so boring vanilla where the AI attacks once and then goes away for ever.

Good luck!