The standard connector for PC audio is a 3.5mm stereo plug, it sounds like one of you pairs of headphones has a 1/4" plug instead.
This adapter will sort it out:
http://www.maplin.co.uk/Module.aspx?...=3.5mm&doy=3m5
You can also get extensions for your headphones as well
1/4" extension:
http://www.maplin.co.uk/Module.aspx?...=3.5mm&doy=3m5
3.5mm extension:
http://www.maplin.co.uk/Module.aspx?...e=2001&doy=3m5
As for wireless heaphones, have a look at the ones that Scan stock:
http://www.scan.co.uk/Products/Produ...=303&OrderBy=1
These should all be available in lots of other places, such as Dixons, John Lewis, Argos, Comet, etc.
Hope this is of help