For your reference on choosing color/model/how much can u fit in here/etc
also, definitely get a hand grip. this would suck without it.
this is the photo with the mbp and textbook inside, things closed. the photo ain't that great but i'm not going to take another photo. basically what u need to know is that it doesn't look like a "bloated tick", imo. after putting these things in, you basically don't have room for anything else. you could fit a small water bottle under the flap w/out zippering the bag shut.
i wouldn't get a bigger bag simply because this is the maximum amount of weight that would be bearable to carry in a messenger bag for someone 5'7 and 150 lbs. and a bigger bag would just look disproportional.