as far as 120 brakes being hard to find, i suggest checking ebay, always a good selection on there, here are some links to a few:
http://www.ebay.com/itm/Marker-Duke-Baron-Jester-Griffon-Replacement-Brakes-132mm-/121004055963?pt=LH_DefaultDomain_0&hash=item1c2c675d9b
http://www.ebay.com/itm/Marker-Duke-Jester-Tour-Wide-Brake-130mm-New-2013-/290803705821?pt=UK_Sporting_Goods_Skiing_Snowboarding_Bindings_CV&var=&hash=item43b54067dd