Endurance is a waste for a Sorc, regardless of spec\tree. If you're equipping a stim it should be based on your main stat, unless you are a tank.
A stim is a near equivalent to another piece of gear.
Getting all of your Datacrons are a near equivalent to another piece of gear.
imo: just as you equip PVP gear to be competitive, stims and Datacrons are a stat boost and you should use them.