Get 4' (1.22m) of shelving with an intergrated hang bar set 12" (30.5cm) from the back wall.
If using this shelving for a reach in wardrobe, please allow a depth of at least 22". If using for a walk in wardrobe, please ensure a minimum width of 58" (this would give you an 'L' shape of hanging space).
If you intend to create two tier hanging, please allow a minimum ceiling height of 85".
If you intend to create long hanging space, please allow a minimum ceiling height of 72", however, if you would like to put shoe racks below, please allow a minimum ceiling height of 85"!
This may not be quite the length you were looking for, but just trim it down using a pair of boltcutters or a hacksaw! You may also find it more economical to buy big and get two or three shelves out of one length!
When ordering, don't forget your hardware!! You do NOT need additional hang bar for this style of shelving!