New buyer Oil pump questions 03

[moonman]

Hello people, I am really close to buying an 03 discovery 2 with 100k miles on it. I have been doing some research and have come across this "oil pump failure" problem that apparently ruins the motor and requires a rebuild or transplant. Is this something that can be prevented? Can the oil pump be replaced so this doesn't happen? I really love the truck I'm interested in but obviously this is a deal breaker if it is just a matter of time before the engine fails. Also are the dimensions the same between the 7 seat disco and the regular disco? Thanks in advance, I did a search before I posted this but didn't find a specific answer. P.S. anyone have a rough estimate on engine rebuild on this truck?