I Almost never ask for help with these kinds of things. I've spend 3 days researching the 2 upgrades I would like to do. Just would like someone to confirm or deny what I've gathered from 5 or 6 sources. The SSD is where I have the most confusion. The sata3 stops the pc from taking advantage of the PCIe SSD drive correct?

So I would get the same performance from 

ADATA Ultimate Series: SU630 1.92TB Internal SATA Solid State Drive - Newegg.com

As I would

Corsair Force MP510 M.2 2280 1.92TB PCI-Express 3.0 x4, NVMe 1.3 3D TLC Internal Solid State Drive (SSD) CSSD-F1920GBMP510 - Newegg.com

or even getting 2 of 

Timetec 1TB 3D NAND NVMe Gen3x4 PCIe M.2 2280 Internal Solid State Drive - Newegg.com

Are the any NVMe SSD that would be worth the extra $? From what I read the understanding I have is that NVMe is way faster but the Motherboard on the 17r2 only offers sata3 speeds so it was a waste?

I Don't really understand the interface difference and don't want to buy the wrong things.

As far a the Memory upgrade going from 8 to 16 GB

Is there really a difference between?

Crucial 16GB (2 x 8GB) 204-Pin DDR3 SO-DIMM DDR3L 1600 (PC3L 12800) Laptop Memory Model CT2KIT102464BF160B - Newegg.com

And

G.SKILL Ripjaws Series 16GB (2 x 8GB) 204-Pin DDR3 SO-DIMM DDR3L 1600 (PC3L 12800) Laptop Memory Model F3-1600C11D-16GRSL - Newegg.com

Thanks for any and all feed back and Explanations 

Alienware 17 R2

Memory: 8 GB

Processor: Intel(R) Core(TM) i7-4710HQ CPU @ 2.50GHz[Cores 4] [Logical processors 8]

Operating System: Microsoft Windows 10 Home