We were going to try a vertical rack, like the one linked by Michael Meyer, but we found rack space in the customer's existing 2 post rack.
I was looking at the link from Toshiba Bob, and finding a wall mount rack that is deep enough may be a challenge. Looking at CDW I did find a 12U floor enclosed rack that looks to be deep enough;
https://www.cdw.com/shop/products/T...ors-Sides-300lb-Capacity/2179475.aspx#POUsually when I see a computer closet with data equipment on shelves, or on counters, with servers sitting on the floors, etc, I think that this is a guy that really doesn't care about their data network. But sometimes when talking to the customer I find that they know it's a mess but they don't have an idea of how to fix it. I usually give them some ideas, and mention that this is something we can do for them.
I am not in sales, but it seems like there could be some potential up-selling. If it was me I would strongly suggest that the new server be put in a rack, and by the way this rack could also hold much of the data equipment and data patch patch panels. Then once everything is in a rack, you could get some new patch cords to make everything look nice.