The trucks that come with the U rails are exactly the same, except for the different sweeps. My experience is that the rails will catch dust, so I make sure to use dust collection whenever possible.
According to the Rollon guys, longer lengths can be achieved by butting rails together, though they come in pretty long lengths. You would havev to grind a "ramp" or "bevel" on the tracks to allow the trucks to movev smoothly which is how the factory does it, but I don't know how easy it is to grind the hardened surface. Pretty easy to cut with an abrasive wheel however..