One thing I'm not sure anyone else has noted, if you are abusing your Z and really driving it hard, I'd seriously consider replacing any brake pipes that are properly corroded and not just the garage trying to get some extra work.
The last you you want if you're nailing it down some country lane, is to stand on the brakes and suddenly lose brake fluid and your brakes.
The two things that are most important IMO, are brakes and tyres.