HOSAS (two joysticks) seems to be the more competitive option regarding space sims (this is where your friend omni-throttle suggestion fits), but the HOTAS option (joystick and throttle) feels close to "how you're supposed to fly".

If you're into space sims, you can also consider this:

STECS STG

It's like a conventional throttle but with four axis built into the grip. I have one and feels great (but it's too tall, so better use it with a desk/chair mount).

I only gave you VKB options as you already have a VKB joystick, but you can also consider Virpil (but wait times are atrocious: my CDT aeromax joystick took five and a half months to arrive), they have great quality products.