They're pretty but, in a collection alone, I think they are too small in scale to hang as above a sofa on a 172" wall, even if they were framed with wide mattes and frames. I would instead consider putting them on a smaller wall or over a narrower piece of furniture (desk, console, etc.)

HI -- Beautiful photos . You will need one more image . Then take to a framing shop and tell them the size of your sofa and they will show you a frame and matt that will fit in a grid of three over three that will fit . Or of the five in a row if you only have the five images . It doesn't matter what size the wall is really . Maybe the height of the wall if it lower than standard 8 feet.

Typically elle4maison is right and you'd use something large over the sofa.
http://houzz.com/photos/206513
If the rest of the wall was balanced with furnishes, you could try this, http://houzz.com/photos/4926300
But since yours aren't as uniform in color, I'd rather go even more eclectic.
http://houzz.com/photos/29944
Or a lot more
http://houzz.com/photos/4378994

The prints are beautiful and have magnificent color. If the size of the print is small that is not a problem. Have them framed with a larger matting around them to give each print a bigger footprint. You have not stated what your aesthetic is so I'm recommending the frame color purely on the intense colors in the print. Black high glass frames with a white matte would be beautiful.

57 inches standard represents where t˙e average persons eye-height is. This 57" also applies to groups of pictures. Think of a group as ONE picture. After you arrange how you want them all to hang (doing this on the floor makes it easier), start with the center picture/pictures and get them at 57" on center. Then surround them with the rest of the group.

1. Measure and lightly mark 57" on the wall (center of where the middle of the collection will be)
2. Measure artwork and divide by 2 (this gives you the center)
3. Measure top of your picture to the tightened wire (a small amount)
4. Subtract "tight wire" amount from 1/2 height amount for the "to the hook" amount. This will tell you how far above 57" your hook should go
5. Lightly mark wall just above 57" with the "to the hook" amount

Search the Houzz photos! See what appeals to you. Maybe you will find a similar furniture grouping as what you have. Bah humbug to rules! My neighbor is 6'8" and he hangs pictures to suit himself, as he should.

I should have told you that all 5 photos are 13 X 19 and haven't been framed yet. Not sure if this makes a difference....

Thanks for giving the size of the photos, I was going to ask that question and then read a big further and you answered it. It does a make a difference. Here is a mock up with an 84" sofa, and I used 18x24" frames with mats, so this arrangement should work with size of photos. I've seen similar photos with crisp white frames and mats and they looked good, but whatever you do would have to work with what's in room.

Thank you all so much!