I would agree with Andy on the fact that 2nd engine should be fine but would wait for the derv experts to confirm and also whether the price is fine.
To save yourself hassle in the future add a timing belt kit so that when you put engine in you know belts, tensioners etc are fine. Will also save hassle being fitted before engine goes in due to easier access.
As Ross says it would be far easier to do an engine swap than repair, take a note of where everything plugs into etc for ease of refitment. You could also strip the old engine of as much ancilleries as you can and build up spares or recoup some cost by selling on
