For a complete system you will need RAIL, HANGERS and HOOKS. Match the hanger colour, in the case of stainless steel and nylon cable this will be just the top bracket, to the rail, usually indicated by the last letter in the code i.e. BOW and BR15W (W=White).
The hanger length is indicated by the number in the item code i.e. under the Avanti system: AN15W meaning 1.5m. Is this long enough for your requirements? The bottom of the hanger needs to come down to at least waist level, as this would usually be the lowest point at which you would place your hook. Remember that stainless steel and nylon cables can be coiled up and hidden or cut off if they are too long but it is not desirable to have a rigid hanger visible beneath the picture.
The description by each hook tells you with which hanger it is compatible. When joining two lengths of Locator classic top rail, you will need a connector (LC), and if the end of the rail is exposed you need some endcaps, available to match the colour of the top rail (white or silver).