Hi Bhawkk! Welcome to the Windows 7 Forums website!
First of all, you're planning on mixing two different brands of RAM, which is usually not recommended even if they have the same specs. The difference in the SPD/EPD chip settings on the DIMM RAM sticks may cause conflict.
Since you currently have Mushkin Blackline RAM, I would recommend you stay with it as Mushkin is top-end, very high-quality RAM. It may not be the most 'price competitive' out there, but the quality and compatibility are bar-none!
You have 8 GB now, which is plenty for 98% of all end-users. Why do you need 16 GB of RAM? IF you're doing very intensive video rendering or Photoshop processing even 8 GB RAM should be more than sufficient, that includes gaming too.