If money is a concerne then go for the LA 318, lot's of speed parts available too.
If not the poly will get alot of "what is that?" from anyone not a mopar fanatic. The one in the above bucket looks really nice. I don't even know if there is a four barrel for it, but obscure is the way to go with hot rods. Even the 318 is rare in the (sbc) world of hot rods.