Depends what you want one for, trackdays, parades?
Youve been a member in here longer than me so there is probably nothing i can add except if you are doing track days then although not essential, its much easier to convert to unleaded as the hassle (and cost) of getting Avgas is a PITA. If this is what you do then spare cylinder heads will be needed so you can revert to either.
Get some pisons and rings as suggested and try to get some detail or evidence that it has a fresh engine... how does the seller know its got a fresh engine?
Dont know the nuances of the NX5 but plenty here do.
Thats my 2p for what its worth
