What is a snappy OS to upgrade to that supports icloud for my iPad Mini 1st gen?

I have an iPad Mini 1st generation and am running ios 7.1.2 I am really happy with the speed of this operating system on my iPad. But, I need icloud and know that if I upgrade to the newest ios, it will be so slow on my 1st gen iPad Mini. What ios would be snappy on my 1st gen iPad Mini that also supports icloud?