The door surgeon

Firstly there are three rating assosiations;

Sold Secure approved -the highst rating that can be achieved is diamond standard.

A second rating to consider is TS007 BSI Kitemark -this assosiation has a star rating system, three star is the highest rating achievable.

Another way you can achieve a 3 star rating is to replace your door handle Mila Pro Secure that achieves a 2 star rating and also replace the cyclinder with a 1 star rating Brisant BS, this will achieve your 3 star rating.

If money is no object in my opinion the highest security that can be achieved, is to replace the cyclinder with a Brisant Ultion and replace the handle with a Mila Pro Secure - Hypothetically giving you a five star rating.(Note star rating only goes up to 3 star) 

If money matters a Brisant BS 1 star is still secure and with 15 years experience I have never seen a door with this lock broken into. 

Another thing to consider when upgrading door security is the door mechanism, even if you had the best handle and cyclinder possible but had a sub-standard mechanism i.e GU Four Roller the door will not be secure. The door also needs to be fitted correctly.