ZionWorx responds very well to a good graphics card and a reasonable amount of RAM. We have had a couple of people notice performance issues with the MS Surface 2 and looking at the specifications it seems to be quite low spec on both those areas (default install. I think you can increase the RAM). Looking at the latest model (Surface 3) I would consider the Surface Pro range which has actual Intel i3 and i5 processors - though not sure about graphics memory.
In terms of actually running ZionWorx this should be OK as it is a normal Windows platform and if you are looking at building playlists rather than presenting with it then the graphics performance is not so critical (I would still increase the RAM if you're able). If possible you could try and test ZionWorx with the hardware before purchasing.