Hey,

Good choice to buy a truck...

Firstly both have the same power,,,,,,6.1 litre engine

try buying the one with twin tyres behind..looks awsome...

there is a 2006 silverado for sale at jaiddah with 2 tyres behind...single cabin...82k ..is witten..driven 35k kilometres...

there r 2 2009 sierra trucks on salwa road for sale..one black one red....

Silverado si mroe conformatble bcoz it has springs on the back chasis..

where as sierra has those plates...which normal heavy duty trucks have...so could be a litlle uncomfortable...

u need more info ...pm me...i have already written quit much ...

but its a very good idea to buy a truck..