Certified GKH Gardening Expert
That would be a tight space for roses. You may be able to get away with it if you use a climbing rose on a trellis.
Use wild roses there tiny, like 6-8 in tops but there beautiful in abundance. Just keep them in good soil cause they eat nutrients like crazy. Other than that use a spinning trellis which will give roses the spin upward to the sun!
Any of the knock out varities that are kept under control will work. Prune as required and although you may loose some blooms, knock out bloom contineously. Since you width is limited, be sure their soil depth is deeper than normal so that they may establish a good root system.
If you look at the growth habits of some miniature roses, the 8 inches might work. Look for short and compact growth habits. Some of them are nicely fragrant too. Again, do your homework on them for such limited room before you buy.
Stan