SilverStone Technology Precision Series Micro-ATX & Mini-Itx Compatible Computer Case PS16B

What is the thickness of the metal used on the ps16,, .6, .8, 1mil? the case i really want is the ps09b. why is amazon not carrying this case?

I don't want any holes on top of my computer cases. Is the top of the case a solid metal sheet, without any grates or holes?

Are the ps16b front case usb ports usb 2 or usb 3?

Does the ps16b silverstone case come with a dust filter?