If ammonia is zero and nitrate is present the cycle is over in the sense that it is now safe to add a small clean up crew if you have diatoms (brown algae) starting, a fish, maybe even a cheap tester frag. There's no reason to complicate it any more than that.
Your tank has a crap ton of brown algae already though, so I'd be adding a significant clean up crew and cut back lighting to just a few hours a day. I prefer to leave the lights off during cycling to prevent the large amount of algae that has cropped up in your tank. What lighting schedule are you using now? What lights do you have?
I'd suggest 4 Mexican Turbo snails, 6 Banded Trochus snails to start. In a couple weeks if they haven't cleaned up the algae I'd add 10 ring Cowries and 10 Scarlet hermits (yes the Scarlets cost more).
Try to scrub off and suck out as much of that algae as you can when you do the waterchange.