OK - some constructive advice for you.
1) You cannot get plug-in MCBs for Wylex fuseboards greater than 40A. This is not a fashion statement, it is a fact.
2) If you have a 60A fusebox, you may not use a fuse or MCB in excess of 32A. This is not a fashion statement, it is a fact.
3) Depending on the particulars of your installation, a 45A fuse may limit you to a cable length to your shower of 10m. This is not a fashion statement, it is a fact.
4) If you do not have RCD protection on your shower circuit, you are exposing yourself to unnecessary risk. This is not a fashion statement, it is a fact.
5) If you approach electrical installation work with the attitude that you have, you are unsafe. This is not a fashion statement, it is a fact.