Hagon are one of the worlds leaders in Shocks and for once Cheap does mean rubbish or poor quality, there fork kits use progressives, Spings, but there rears are built in the UK using quailty kit, i have always used them on custom builds as for longevity most Hagon Shocks will more than likey outlive the bike, ride quality is awesome and if you give them all the specs you want they will custom build them for you - i see you have the link already, the one issue is that the progressives will most likley be cheaper as shipping from the UK could hurt unless hagon have a US importer and supplier