need help deciding a motor

Do whatever is cheapest and easiest for now and save up for the set up you want.
Drive it now and you won't lose interest.
Don't go for the all or nothing approach, or you might lose interest.
Good luck and tell us how it goes.
Forget the big block in an early a body unless you want to end up with one forever, a waste of money and effort for what you eventually want, which is a modern hemi you say.
My 2 cents.
Tom.