the numbers that come after the "PC3" refer to the total bandwidth of the module. For this type of memory, a higher number represents faster memory, or more bandwidth. Will you notice a difference probably not.
Whether the frequency/speed will matter or not really depends on what you do with your system, if nothing more than email, light typing, surfing, etc then 1333/1600 will be fine, gaming would suggest 1600/1866 and if you multi-task, use video, image, CAD, VMs, apps or anything with large data sets then 1866 and up......big thing is to make sure of what DRAM freqs your CPU can handle - many people here seem to think if a mobo says it supports up to say 2800 DRAM, then they can just pop in 2800 and all should be good - which is just wrong - the CPU has to be able to carry the sticks and amount of DRAM at the freq
My question is, the number after the RAM, should I get 10600, 12800, 14900 or does it even matter ?
Yes, the numbers after "PC3" does matter as they denote the memory bandwidth. The memory frequency can be calculated by dividing the memory bandwidth by 8, for example, consider you have a PC3-12800 the frequency is 1600MHz. The frequency is important. The processors which your system supports does not support above 1333MHz (officially) but it can go upto 1600MHz or 1866MHz (unofficial) which is a gamble, as it may or may not work. So stick with 1333MHz (PC3-10600).
No, Crucial scan is only concerned primarily with what they sell, and doesn't take into account what the CPU/mobo can actually use. What mobo and CPU do you have? If the GigaByte shown in the pic is yours, then check the specs - for ver 4.1 of the mobo
it supports up to 1333+ with an OC to the CPU....so in effect they are saying the sticks they list will 'work' but you'll have to OC the CPU to get them to work - and in the case of 2133 prob never going to happen....A few 8350s can carry 2133 sticks but not a ton of them, say a 965 is about the lowest AMD that will carry 1600 sticks, all the FX CPU should carry 1600, and the higher end *120 and up can carry a pair of 1866 sticks, generally.