Though I want to see Sailfish on this device too, look at this (LineageOS 14.1 20170609 unofficial):

https://forum.xda-developers.com/nex...-2012-t3530261

This works very good and is really fast. But try to install an older image first like 20170315 - second thread!!! and then upgrade to the newest one (see whole thread). When you try to install the newest one directly you may have problems going through the startup wizzard (nobody knows why)

[Update]
Before installing think about formatting to f2fs and install ftrim (like trimmer) afterwards. This just boosts up the speed. All stuff is discussed in the thread