The 2006-2007 WRX 4-pots will require new wheels and different rotors. The front XV rotors are 11.6 inches in diameter, while the WRX 4-pots are 11.5 inches in diameter. The stock wheels don't fit over the spokes.
Also, the stock braking system with a sufficient boiling point brake fluid, pads able to take quadruple-digit Fahrenheit temperatures, and grippy tires are all that's truly needed for great stopping power.
"Why would I want to profess my feelings for some 3D girl?" - Tomoya Aki from the anime Saekano