I am new to this forum but a long time user of AutoCAD and Solidworks.  My current set up is a fully loaded Dell Precision 7730 that I dock and run two Dell P2419H monitors.   So far its been working out well.   I often use my laptop as a third screen.   Though seriously thinking about switching to a since large curved widescreen monitor.  The  7730 has an 18″ screen is plenty big and the full size keypad with side number pad makes it almost seamless when I switch from being docked with a standard keyboard to on the go with just my laptop.  I use a Logitech Bluetooth M570 trackball, both when docked and when on the go.  I’ve yet to find anything that works better for me.