b3 steping means it has been revised for the chipset problem so its good to go. Have a look at this board. It's a Asus Sabertooth p67 motherboard. I have the x58 version of this board and love it. It's great for overclocking you can run sli or crossfire.2x16 slots
I was just saying I like mine and the plastic thing is for looks I guess. I would Just get something from Asus as they have been really good boards for me. The Asus board you picked out is a nice board go with that one.