Well, I got the perc H200 and it worked out of the box as a RAID controller. I attempted to flash it with IT firmware. It didn't work. (Of course it erased as it should. )
I suppose I need to get real dos (versus free DOS) on the USB drive, and give it another shot on an older non-UEFI Mobo.
Got the Perc H200 flashed, with a bootable USB stick created with Rufus and free DOS (included with Rufus). I flashed the H200 to IT mode using this -> process, the same as used by @GTvert90 . For some reason, sas2flash.exe failed on the Intel mobo (the server's mobo). With the H200 installed in an AMD M5A78L Mobo, using the same software and process, the Perc flashed without issues. (Both Mobo's are UEFI.)