2011 130 Puma 2.4 rebuild or used engine replacement

Too Long Didnt Read TLDR: Car needs engine rebuild or used good engine, what are your thoughts?

Finally bought my dream car, a defender! Been dreaming about this for years. Regardless, the one I bought is in pretty bad shape even though it only has 30,000km on the clock, pretty sure the clock is right and the previous owner just didn't treat her too well. It needs either a complete engine rebuild (cost of parts + labour) or a known good used engine. Honestly lots is wrong with the current engine and I initially set my sights on buying a replacement engine and having it installed. I understand I haven't really given you much information about the current state of the engine but I want to know your thoughts on engine rebuilds is the way to go or just get a known good used engine. Cost is not really a major issue since I factored it in when I bought the vehicle.

There is a plentiful supply of delivery mileage 2.2 puma engines, at very good prices, as a lot of late models are chelsea tractored with v8 conversions. You would also need to factor in a new ecu (again plenty available). Check out eBay and go shopping.