I have bear brakes all around. Street/track setup. What kind of brake fluid would be good to use?

 

whatever the manufacturer recommends. However you need to check with the mastercylinder as well.
DOT3/4 is compatible with each other as far as I know (whatever handles 3 can use 4). DOT 5 is totally different beast which I usually keep my hands away from unless specified by manufacturer.
You'll have to check with them to be sure

 

Probably DOT 3, DOT 5 as far as I know was a GM deal on some Corvettes.

Use good fluid, and if you're going to do performance driving then something like Wilwood 570 or EXP 600.

 

Dot 5 is synthetic and in some cases may require special brake lines. As mentioned it's not compatible with DOT 3/4.

3/4 are the same just that 4 has a higher boiling point.

I would recommend DOT 4 for high performance brakes or if you are flushing your brake system out and replacing the OEM brake fluid.

 

DOT 4 isn't much higher than DOT 3, good for really hot environments and moderate performance. If it's going to be raced though, definitely use something like Wilwood's 570 or EXP 600. DOT 5's main issue is compatibility with seals. It causes most of the o-ring seals in master cylinders to swell and fail, causing internal leakage, unless they're designed specifically for use with DOT 5(it's a silicone based fluid).

DOT 3------ boils dry around 400* F and at wet saturation around 285* F
DOT 4------ boils dry around 445* F and at wet saturation around 310* F
DOT 5------ boils dry around 500* F and at wet saturation around 355* F
Wilwood 570 boils dry around 570* F and at wet saturation around 310* F
Wilwood 600 boils dry around 625* F and at wet saturation around 415* F

Wet saturation is when the fluid has absorbed water to 3.7% water by volume.

The 570 is good for most mild/weekend race applications. Same wet boiling as DOT 4 but with a substantially higher dry boiling point. The 600 is quite a bit more expensive(2x the cost of 570), but blows most everything else out of the water(commonly used fluid in professional racing). Dot 3 is what pretty much everything uses, DOT 4 is good for a street performance car with moderate brake upgrades, or light track use(occasional drag strip, some autocross etc).

From personal experience over the years, I've found the 570/600 can run much longer service intervals on the street than DOT 3, it takes a lot more fluid contamination of moisture before it loses effectiveness, and it doesn't break down as easily under high heat.

If you're going to use auto parts store fluid, then you might as well get DOT 4, it's a better version of DOT 3.