If you want to be playing games well on an Ultrawide, you'll want it to be probably something like a 390/Nano/Fury or 980/980Ti (depends how much FPS and Vsync means to you!). For small build I definitely agree with the above that the Nano is the most suited for the job.
In regards to your feedback in regards to stock, thank you for letting us know. It is good to get feedback from customers to know how to improve. A lot of the time if specific items are required they can often be sourced if requested, but I can appreciate that isn't ideal if what you want isn't on the site at the time you want to order.