We have contacted OKEX but require more volume, apart from that we would be first looking at Huobi, Kraken & Poloniex.
I think you just saw a nice place to begin your journey, but you realize that you'll need funds to be listed there, right? Those three exchange that you said is the best after binance. Once your token registered there, you will have a great community and volume. I hope you have built a community from now on.