Matt,
Welcome aboard ! I would think the best thing to do is going to depend on which engines are available to you. Small Block Chevy engines seem to be the most popular almost anywhere, so that would be my first guess. It should be fairly easy to swap in a 350 Chevy with a matching automatic transmission. Best thing to do, no matter what engine you decide on, would be to find a "donor" car so that you can get all the brackets, pulleys, motor mounts etc.
Hope this helps,
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