16GB RAM? You sure it's the memory that's holding you back, and not the underpowered GPU?
The computer I had at work for a while (got a laptop recently) was packed with 32GB of RAM, a 250GB SS drive for the OS, 1TB HD for files, top of the line i7, and 2 7500 graphics cards.
All that bring said, I observed my ram usage....
7-8GB for Chrome sometimes (lots of tabs).
1-2GB for Illustrator
1Gb for PhotoShop
And then another couple GBs for other applications like Visual Studio, Outlook, Sublime Text, etc.
Also, I need to be able to build VMs on my machine so I can work on various development projects at work.
Although les powerful then the tower I had, the laptop I got recently is just about perfect for all of this. And the specs could certainly be packed in a SP4.
I use an identical laptop at home for freelance work.