If you currently have 10.5 discs, you aren't going to notice a huge increase in stopping power by swapping to 11.75. There will be some advantage because a larger diameter rotor has more leverage, but not a lot. However, repeated stops will begin to show a difference with the bigger rotors better able to absorb the heat.
Just like tire compounds, pad compounds also matter. OEM type materials tend to provide decent all around use, but if your putting a lot of heat into the system, you may need harder compound pads to maintain bite.
The 11.75 rotors with Wilwood calipers provide larger diameter rotors, less unsprung weight, and a wide choice of pad compounds you can tailer to your driving style. Pads for Wilwoods tend to run around $45-50 a set. Viper calipers can do the same, but the pads tend to have a wider range of prices and can be more expensive. I have no experinece with carbon metallic or ceramic pads on the OEM single pot caliper set up so will defer to others experience with them.