1 Piece scooter are bars are the choice of any serious rider, the added strength, stability and feel mean that you can attempt tricks with a lot more confidence. 
Steel or chromoly bars offer a great finish and maximum strength for monster tricks.
Aluminium bars are strong enough to take some real punishment but are much lighter than their chromoly counterparts.
Here at Skatehut we have a wide range of bars that cover the need of every rider. We stock all the best brands available in the UK.