For what it's worth I have a Highway card in my A4000 using Poseidon. Connected to the Highway card is a PS2->USB keyboard/mouse cable (fairly cheap on eBay). To this I connect my Trust 300KD wireless keyboard and mouse combo.
All works perfectly, through a Belkin 4-way KVM switch. So, I have 4 machines using the same wireless keyboard and mouse, including a PC, a Mac Mini, an AmigaOne and an A4000.
Don't know if that helps any but that's how I get wireless keyboard and mouse via USB on my A4000!
