Lineage 2 is not very demanding graphic wise (gtx 840m should be fine) but it sucks at multi thread computing, even if you have a quad core cpu, it will only use 1 core. Nevertheless, the most advanced CPUs you can find in a laptop are the i7 series. Also for fast porting and loading times I would recommend you a SSD drive or a large amount of ram or both.
If you want 60 fps in Aden with high details than a laptop is not what you need.
I use an Asus G75VX with i7 3630qm, gtx 670mx, ssd and 32gb of ram. On FullHD resolution I get with high settings around 25fps in Aden and 60-80 fps anywhere else on the map except sieges where it drops to around 30 fps.