In reply to lumu_tit:
Buffalo is your fibre pile/pertex friend.
http://www.needlesports.com/catalogue/content.aspx?con_id=d1318703-b1cf-4db...
Couple of links below to specific trousers
http://www.silvermans.co.uk at £80
Cotswolds have them at £93
Needle sports, great shop, have the Techlite version at £60.
All of the above have a pertex outer for windproofing which solves the original weakness of fibre pile clothing.
I sold the thicker salopettes. Great for winter belays but just too warm for anything else. Can't help if you just want fibre pile without the outer pertex. Sorry.