If you are confident you’ll have a working used engine for $1100, that seems a good choice. Eventually of course it will wear out and have to be rebuilt, but you can worry about that then. Getting the vehicle in use seems the highest priority here, so you’ll have incentive to keep the project moving ahead. Otherwise if it just sits there unused, it will be easy to decide it’s not worth continuing. A quibble, I’m not so keen on that color combo and artwork. Are you thinking of an improvement to the paint job & colors? A artful paint job will really make your project pop and be noticed.
Here some puzzler questions: Do you know what the “W” means in 351W? There’s another 351 Ford engine, called a “Cleveland”. Do you know the difference between the two?
Make sure the interior of the vehicle, including the engine compartment, remains dry while the work’s in progress. Might pay to invest in a cover if you plan to keep it outside.