read through a lot of posts, but most get a special fluid that is tinted.\
is it ok to just use the synthetic dot 4 brake fluid that is readily available at the parts store? like valvoline or prestone?

I'd go w/ Valvoline vs Prestone.
I know Prestone has lower dry/wet boiling point vs Valvoline.

http://www.rollyourfender.com/drop/Brake_Fluid.jpg
(Price might have changed)

Unless you track your 5 like a crazy and you feel you are boiling the fluid then I don't see the need to use "high $$$" fluid especially if you just daily drive it.

I used Valvoline Synt Brake Fluid (Autozone) on my STi track day car and never boiled it and I'm planning to use the same w/ my 545i.
If I want to spend more then I'd go w/ ATE Super Blue but Valvoline is easy to find locally and the price is RIGHT :D

I'm using Ate Super Blue in the 550i with no problems at all. But I do agree with salaki that other (cheaper) fluids from the parts store are just fine for a street car.