The 351w in a Foxstang is tried and true.
Easy, reliable, easily fuel injected, fits like a glove, some 5.0/302 parts swap, easy cheezy.
However, it's been done to death... If you want something different, and money is no worry,
do a Cleveland. They weren't around to ever get EFI support from the factory, or roller cams
for that matter. But with enough fabbing and money, these things can be done too.
Don't even bother with the 351m/400 engines (externally identical).
They are truck engines with very little/no aftermarket support for use in cars.
If you know the difference between a 302 and 351w, same basic engine, just a little taller/wider...
Well that is the same thing between the 351c and the 351m/400. The Ms are the same basic engine,
just taller and wider. If you can fit an M engine, you can fit a stroked 460! That is why the Ms never
got support. Why run 400 cubes in the same size package you can run 460? Especially when 408 can
come from a much smaller package called Windsor.
Anyway... both 351c and 351w are good and are do-able.
351w is the 'safe' route.
351c is the 'dare to be different' route.
Good luck
Dave