The 318 is an upgraded version over the 302.
The 318 is an air/spring fork, it compresses with spring, and de-compresses with air if i am correct. Yes it has motion control and lockout, and has 100mm.
The Tora 302, has 80-130mm and is U-Turn/Motion Control but has no lockout. For some reason 302's retail more expensive here then 318, but the 318 is the upgraded version of 302, and RockShox claims it performs better.
Hope this helps.