Which one of these skateboards is best?

I'm drawn between a few boards and I had a few questions. I'm a street skater, so I just skate my local roads and pop flips and stuff. For one, what size board should I get? I know they rock from like 7.45 to 8.45 but what's best? Secondly, how good are impact boards (by almost)? And for the trucks, how do I pick the best size? I know there's the hi's, mid's and low's, and then the inch size, but how do you pick? And on the bearingns, what ABEC rating are ceramic bearings? I know they're pretty legit but most don't have an abec rating. Thanks alot!