I picked up a 13" Late 2011 MBP with 10.8.5 from work for $400 and am looking to put a SSD in it. I was planning to get a Samsung SSD but not sure which model I should get. 840 or the 850? EVO or Pro? I'm planning to install Yosemite so was going to make a bootable Yosemite flash drive before I switch drives. Any tips I should know about?