3 Color Questions

I'm a medium blonde color right now (my natural color is a light brownish/dark blonde color). I'm looking to get to a lighter blonde shade (like Reese Witherspoon in Legally Blonde or Kate Hudson in How to Lose a Guy in 10 Days). I know that Colorfix takes off artificial pigment but would it be a good idea to use on my hair before I dye it with the lighter color?

Also, I usually get red or gold tones in my hair so I'm thinking if I want to get lighter w/o those ucky colors I need to use 40 volume developer. Yes, no?

One last thing... anyone know of any good brands (and the numbers) for blonde hair color (like the two actresses I mentioned above)??