Another good choice, especially if you want to avoid Win 10 (which security expert Steve Gibson described as a “flying tu^d”) is an off lease Lenovo Thinkpad. These older but very capable business class machines can be had at bargain prices from local re-sellers, on eBay, and on Amazon. They are well made and robust, ideal for the shop.
Furthermore, because of the kind of machines they are, accessories and parts are readily available through Lenovo, IBM, and a world of third party sellers. I picked up one for use with my XXL for $200, but liked it so well that I ended up adding mobile broadband, an extra battery for use in the bay, 16gb ram ($60 on Crucial) and a Blu-Ray drive.
For Linux lovers they are well supported - Ubuntu even knows which model Thinkpad it is installed on. I’m running Windows 7 Pro on mine, but with all that memory, and plenty of processor capacity, I am also running Linux and an extra Win 7 virtual machine (for testing) under Virtual Box (free).
I just thought it might be interesting to point out the diversity of good options we can choose from. BTW: I wound up getting a very long USB cable and assigning control of my XXL to a Mac Mini Server on my lab bench which is normally used for operating electronic microscopes and a set of Logic/Analog Signal Analyzers. My Lenovo has since found other tasks. although it works great with the XXL.