if u get the cabinet a compressor is all u need apart from abrasive. minimum size would be 14cfm flow with 3hp motor look round on ebay see if theres anything cheaper the same size it has a suction gun inside which is ok a bit slow mind i use cabinet with suction gun and also pressure fed pot with blast hose and carbide nozzle more powerfull but its all down to price and how often u use it /look through the compressor threads theres a lot of info by other members on the subject all verry interesting
the filter ring is a base of a gas bottle .filter from hardware shop of frying pan with handle cut off . the suction gun i cast in aluminium of an old worn gun machined the brass fittings and made and hardened the jets. its lasted a lot of years with a lot of use the fan is a woodchip dust removal fan bought for 20 quid