Alright guys, trying to find out if this plan makes sense at all, and if it doesn't feel free to pop me in the nose

If I buy a car with reasonable mileage, for in my price range, and then swap it out with a used engine from theeurodepot.com, would that make any sense. What im trying to say is, would this help me in the long run, would I gain any advantage? Also, has anybody purchased anything from them, just to get a non-biased opinion. Again sorry for the newbness, also what is VANOS and non VANOS, and which do I want? Thanks for your help in advance guys!!!!