Low light SLR
In addition to what the guys said, you need a "good" low light sensor to produce quality images with the least possible noise and much details and among your chosen bodies the D7100 is a good compromise unless you wanna spend a fortune on a top end FF body and a lens.
|Antz by Deadfisheye|
from Animated Film Title
|The Ladder - Fort Worth Museum of Modern Art by RJD13|
from Lookin' Up!