I think you have solid hardware there, I personally need more than 256GB of storage but if you can manage without an upgrade it's all good there.

Concerning distros, I am absolutely in love with the visuals of Kali 2.0, and I think the system is quite easy to maintain while providing some customization, granted not as much as slackware or some other OS's. Kali 2 is quite functional, but I always dual boot with a Windows OS for Steam and other exclusive programs

Good Luck with the laptop!