Rev Or Laravel? how to change password encryption?

[Solid]

Hello, I've been using cosmic the last few months and honestly i don't really like the structure. Do not get me wrong i love the cms as it is pretty stable but due to the cms being overused i am looking for my own theme style.
I was looking to move from CosmicCMS to either REVCMS (Which ive used sense 2012) or create a Laravel framework CMS. I know Revcms is outdated with PHP & Mysql but was wondering if it was worth upgrading?
Also if i move cms's I would need to change Sha2 to Md5 which isn't really a good thing. I am honestly looking for opinions here. I want my own custom theme (which I can create my self) Looking for a good backend.

I've never used Laravel and do not know the code language.
Using ArcEMU.

 

[Sledmore]

In response to the query about password hashing:

When I moved my hotel from sha1 / whatever UberCMS was using to bcrypt, we decided to add a piece of code to the login to validate the password and then rehash it as bcrypt if it hadn't been already. There's no harm in doing it that way and just preforming a quick check on login.