Outer Limits 4x4 Board

I'm changing brake fluid in the truck and was wondering what sort is best to use? Anyone have brand recomendations?

Also, should I use dot 3 like the cap on the fluid reservoir says to or is it ok/better to flush it out and use dot 4 or dot 5 or 5.1?

Thanks guys.

Dot 4 is fine and widely available. Any decent make and it is a good idea to flush about a litre of it through all the bleed nipples while keeping Master cylinder topped up. Start from wheel furthest away and so on in. don`t pump the pedal to the floor on downstroke but only 20 or 30 mm, just enough to eject fluid from bleed nipples. This prevents master cylinder seals from damage on the ridge that may have formed in metal sleeve inside the unit. Don`t need engine on or anything. This will do the world of good as fluid only performs for two years before degrading and causing damage /rust to components as well as poorer braking.
Alex