Android Studio laptop

I need to purchase for university a laptop to develop android apps on during lessons since the pc we have in our classes aren't good enought to handle android studio decently so i'm looking for a second hand computer to get the job done without spending too much money on it. My main issue is not knowing the "Optimal" performance to look up for android studio + AVD usage while staying in my budget, first of all is how much ram should i be looking for? Will 8GB be good enought or i need the extra stretch for 16GB? As for CPU i have two choices, going for older (2011-2012) i7 but with more core/threads (example i7 2630QM 4/8) or would a more recent CPU do the job better (i7 4500U 2/4), will android studio benefit more from single core performance over multi thread? As for the OS i will probably go with a Linux distro installed on an SSD + HDD (will remove DVD drive). Thank you very much for your help