The V8 isn't new and goes back to the mid nineties XK8/XJ when it was 4.0L
4.2 2002 to 2008, then 5.0L to date
The V6 is the V8 with one bank of cylinders lopped off.
All were paid for by Ford, but the distinct characteristics are Jaguar/JLR.... Built in Bridgend, and production will come to an end mid 2020.
I've had 4.0L, 4.2 L s/c, 5.0l s/c and 3.0l s/c and can confirm they are great in supercharged form.... Turbo engines have a very different characteristic, and I would have s/c every time. The Lotus twin turbo V8 was fun, but personally would avoid small capacity, hi-powered engines based on 20 years of experimentation.
The SVR is great, but so is the 3.0L s.... Both are the cream of the crop....