Please help... Engine decision?

[Nick.V70]

I am building a cruiser 70' Chevelle, need help getting some direction on what to start looking for as a power plant for my car. One thing I am pretty sure I want to see under the hood is a big block but nothing is set in stone and looking for help setting a direction.

How do people go about figuring out what to use and how to set there buying budgets for it?

Is there a popular engine combo I should be really taking a look at?

And I know it all comes down to money....I don't even know yet where I need to be on this and that is why I am lost. I would be OK with spending money but of course i just want the most for my money.

Thanks in advanced guys!!