I have the following installation:
2 laptops, both with wireless connection to a BT Voyager wireless modem/router. This has a Virgin.net broadband internet connection.
A plug-in bluetooth link to the (rarely used) printer. This is interchangeable between the laptops, but does not give me a readback of the ink levels in the printer (might be the age of the printer?)
A logitech cordless mouse if/when I need it.
For the hell of it, I once ran all these wirless connections, plus a VMC PC card, another mobile phone and also a DECT phone all in close proximity to eachother. No interference or other problems at all!
I wouldn't bother trying to interface your existing kit, now that peripherals are so cheap...
The only wires I now have are from the mains to the laptop and from the mains to the printer.