Pinto, for a couple of decades I've been winning the write-a-letter-to-Mom race using my Compaq 286/SLT, DOS and WordPerfect 5.1. Start up to the DOS prompt, launch WP51, type address block, Dear line, two paragraphs, print on a Deskjet and sign it. Until Win8 and SSDs arrived, I was beating our so-called fastest PCs.
And yes, forget the MFM... that's the Compaq 386/33, and it's a power-hog. With those two external full-height 5.25s, though, it's a great wintry, snowed-in cabin warmer!!
I found the 486s were all IDE. I'm sooo sure those IDE-SATA connectors will do just fine!!
Mikey's wife checked in. "Yes, put those shoes on hold for me - I better hold off - he signs checks for billions, and will be snarl when I show him the cutest $300 pumps!" Men.