Whats the deal with the head gasket then?

Is the replacement different to the original to prevent/cure the problem or is it liable to need doing again?

I'm sure she'll be intrested as we cant find a good MX5, she wants the face lift model but all the ones I've been to view within her budget were dogs, typical women, found loads of old shape ones with pop up lights but she wont have it, the newer it is the better it must be