Valve Cover Gasket Change Questions

[dprime]

Im changing the valve cover gaskets in my 2004 I-35. The car has 125k miles. As long as Im that far along,...
1. Should I just go ahead and change the Valve Covers as well (to avoid future spark plug well oil leaks)
2. Is there any reason I cant use Nissan valve covers VS. infiniti Valve covers?

Thanks.