I went from shooting available light to off camera flash for VB last year and really liked the results ... of course the venues/leagues I shoot have no restrictions against flash.
I love my 85/1.4, but for this purpose, there isn't that much of a difference between the 1.8 and 1.4 - only 2/3 of a stop. Optical quality wide open is a better on the 1.4, but I don't think it justifies the extra price tag. For that price, I'd rather save up a little more, and get a used/refurb D700 for the extra ISO performance.
+1 to shooting manual. Same thing as weddings in a dimly lit church. Set up your exposure ahead of time. The light isn't changing, but the meter is easily fooled by changing background, or dark/bright uniforms.
