I have replaced my front brakes with ferodo pads and Brembro rotors (8k miles ago) and now need to replace the rears

I would like to go with a slotted look (really just for appearance)

Would there be any problem changing out the Brembros also for a slotted rotor or do I need to change out the pads for proper functionality?

 

Changing pads or rotor as one does not require you change the other.

 

You can use whatever pads front or rear with any stock sized rotor whether slotted or not.

Yes, slotted is mostly for looks. Take your pick. Zinc plated rotors might look a bit better with less rust until the finish wears off either with time or with heat from use.

I assume you mean you are changing rotors in the back for slotted and want slotted rotors for the fronts too which is fine.

If the front ferodo pads are not too worn then you can keep them, just clean them off well.

 

Anyone ever heard of http://www.sportbrakes.com there prices seem low they use Brembro blanks front and Zimmermann rear and machine them how you like.

I am thinking slotted and dimpled but really dont know. They have some good comments out on the web but $220 for a complete set seems way too good to be true.