Re: Few comments
"Just last week I hunted high and low for < 32GB IDE hard drives because a customer had one of those 6-figure CNC machines with a DOS controller and the old drive was dying. The 200-500GB drives I had didn't work and didn't have a jumper for 32GB compatibility..."
I can (and HAVE) solved _that_ problem with any modern SSD (or other SATA drive) and a £6 IDE-SATA adaptor and so can you if you bothered to RTFM (if the interface is a PATA 2.5" then use a MSATA drive and a 2.5" PATA carrier)
The fact that you don't know how to do it shows you haven't done your homework and the fact that you're attempting to do this with old mechanical hardware is simply buying more trouble a few months down the line.
SSDs solve the vibration problem permanently and end up with so many spare blocks that wear levelling essentially means even the smallest one you can lay your hands on will last forever (don't use HDD to SD adaptors. These will die eventually unless readonly and you can't make them report as 32GB)