Need some more information, benchwork design and current track plan will help the folks who are good at design get a handle on what can be done in your situation.
Good luck,
I put a manual turntable at the end of my staging yard. This yard stages trains both east bound out of Weed and west bound out of Klamath Falls back to Weed. Since it’s a staging yard, I used a Peco On30 turntable. I will however provide some scenery for the yard including the log dump at Weed. Peter Smith, Memphis 
wherever you put a turntable make sure it is near the front of the layout so you can visually inspect the indexing.
Whenever the subject of turntables comes up i am reminded of the story of the legendary Supt. Charles Minot of the B&M and later the Erie. At one station he received a dispatch that a locomotive’s tender had derailed into the turntable pit and that the yard crane was going to lift the tender out. At the next station he received a dispatch reporting that the yard crane was now in the turntable pit and that the steam crane was being fired up to retrieve the situation. Minot wired back, “Leave the steam crane where it is. No more room in the pit.”
Friend of mine put a new diesel in the pit once, just a few minutes before they hogged out. Sup. came out, Started ranting and raving, sent crew home, made the other guys jack the engine out…
Bout the time the last of the crew left the property, the Sup. figured out that he just sent the RELIEF crew home, and the guys un front of him no longer even had enough time to get the ties to build the engine back up with.