Been mass breeding but I don't know what to mass breed next.

I have:

-Shuckle
-Houndour
-Growlithe
-Zorua
-Gligar
-Purrloin
-all of the dragons
-Aron
-Larvitar
-Litwick

I have adamant/modest synchronizers. Which pokemon would be best appreciated being tossed out into the abyss that is Wonder Trade?

Also what pokemon should I try to get my hands on to breed?