Hello, I need some advice and opinions please.

What else should I know about barracuda’s is the 318 not a good engine for them? Prone to anything in terms of rust spots?

ANY small block is an excellent foundation. IMO though, you could find a numbers 68 340 car for probably close to the same money. That is, IF you're interested in that kinda thing. That's just to give you an idea. I wouldn't pay 18500 for that POS no time no where no how. lol