Corsair Vengence and Kingston Hyperz Fury are good brands/models.
AData is less well known, I would trust them less.
C10 is better then C11, C stands for CAS its a measurement of how many DDR clock cycles it takes to access memory stored in a piece of DDR RAM.
DDR memory for Intel i3, i5, i7, socket 1150, 1155, 1151 CPU's should be purchased in matching pairs.
DDR memory for Intel i7, socket 2011v1 - 2011v3 CPU's should be purchased in matching quad sets.
Current AMD FX and AMD A series CPU's should be purchased in matching pairs.