Need help on Black water valve assembly- 1966

[CtRobert]

So i'm to the point of needing to buy the entire valve assembly for a 66 GT. when I got it the valve was ripped out of the tank. replacing the tank with an ABS above floor similar to original. so the penetration will go from the floor, through the belly pan and then dump I'm assuming either straight down or curve 90 degrees and come out the street side.

So here are the questions:
1. Valterra, Thetford or other type?
2. What parts do I need as I'll be plastic welding this to an ABS tank?
3. Straight down or side/rear discharge?

thanks, Rob in CT
860-663-2004 home office