Thank you for all your wonderful replies, insights, and suggestions. Budget is our major obstacle, and your help is appreciated.
I am currently trying to clean up a donated Roland D10 Keyboard(wonky switches, etc). We also picked up a Yamaha PSR-GX76 for $20, but it is better suited to students than for a workstation / arranger.

Coincidentally, I am an 'old timer' with Band-in-a-box, having purchased an early edition (on clearance) from a now defunct music store (MARS). I wound up using their "Power Tracks" to do multi track recordings far more than I used BIAB. But BIAB does do well with MIDI files and has a Karaoke window.

Friends in a far state are in a similar predicament and they were considering an arranger keyboard (w/ MIDI or Song files) to do an outreach ministry in nursing homes, etc. Obviously, the top of the line equipment is wonderful. But what would be the recommended MINIMUM arranger keyboard? (New or vintage)

Addendum: Has anyone used a MIDI to USB Cable adapter to connect legacy MIDI to a modern PC? Anything to look out for?

TIA.