Target and the fine Apollo WT 1 & WT2 wall supports (http://www.apollohifi.co.uk/)are available from May/Justice Audio in North America :
http://www.mayaudio.com/mayaudio/home.asp
British Audio manufactures and sells the Wallnut II support:
http://www.hi-fi-accessories-club.mcmail.com/wallnut2.html
Mana ( http://www.mana.co.uk/ ) is available thru Flat Earth Audio :
http://www.flatearthaudio.com/
Quadraspire( http://www.quadraspire.co.uk/index_main.htm )makes an unique wall unit in their Q4 range.
It is distributed in the US by The Sound Organisation,USA:
http://www.soundorg.com/
On the pre-owned market,also consider wall supports from Sound Organisation & Audiotech.
Best,
Ken
GreaterRanges/Neuance