Need help choosing RAM for ASUS Series Desktop and Can we install at home easily?

PhotoMom2020

I have ASUS Desktop PC K30AD_M31AD, M51AD, M32AD Series.  It has 8 GB Ram and I need to upgrade. My photoshop and lightroom editing has slowed down so much.  It's driving me nuts!  I reached out to Best Buy - virtually - and was told what part I should get, but don't know if it is a good deal.  Tried looking at Micro Center for similar, but seriously there are many options and specs. I'm lost with getting computer parts unless it's a mouse/keyboard. 

BB recommended CORSAIR Vengeance 15 GB 2 pk, 1.6 GHz DDR3 DIMM Desktop.  The cost seemed higher (almost $140) than I thought it would. What does MicroCenter have that is appropriate.  I need something that is going to speed up the processing so I don't pull my hair out. 

Also, my husband said he can install the new cards. Is it that easy? He is pretty handy, but I just don't want this computer messed up. 
Thanks so much!

Photomom2020

Ian

Greetings. What specific model of ASUS it is for? Your post lists 4 different models, we would need to know the specific model to make sure you are getting the correct RAM for your PC.