Basically anything that works fine on summer grasses will be fine on Zoysia, its almost as impossible to kill as Bermuda. Its a bit late for preemergent but you should get it out in a hurry, and just the preemergent by itself.
Weed & Feed will work if you put it out on a wet lawn, then spot spray whatever is left. Between that and the preemergent you should be good. Then put out more preemergent in September. I really think Weed & Feed (2-4D) is a early warm season (June) weed killer, and tend to use Bonus S first, as the MSM in it wipes out clover, rye, and damages fescue that might pop up in early Spring.
Otherwise Zoysia just likes nitrogen, so a straight N fertilizer every 5-6 weeks is all it'll want besides water.