Not sure if they have that size exactly but almost any pottery supply house sells kiln wire in either rolls or pre cut lengths for electric kilns.

Cheers.

TomW

The Truth is the Truth, even if no one believes it; and a lie is a lie even if everyone believes it

INFO FROM NATIONALELEMENT.COM website (also a parts supplier)
Coil Elements
By far the greatest number of heating element designs involve the use of round wire close-wound on an arbor or mandrel and then stretched to form a helix of at least twice the close-wound length. Having selected the proper NIKChrome® alloy, the next step in designing such elements is to choose a size of wire which will operate at the desired temperature and which can also be coiled to fit within the physical space limitations of the device. In most cases, some precedent will have been established as a basis for determining the proper wire size. Lacking prior experience, the data presented in the following tables will be helpful. To use them, proceed as follows:

Calculate Wattage-The approximate wattage required to operate a given device at various temperatures can be determined from the Current-Temperature Relationship Tables which list current carrying capacities of NIKChrome® resistance alloys in most commonly used wire sizes. First, select a test wire size that "seems" suitable for the application. Then, knowing the voltage on which the device is to operate, calculate the wattage by multiplying volts times the amperes shown ( W = E X I ). These tables may also be used to estimate amperes required to heat coiled Chromed elements to different temperatures.
Determine Wire Size-From the design established for the device, check the space dimensions allowed for the element to find out (a) the approximate coil diameter or size of arbor to use, and (b) maximum lineal distance available for the element. When these factors are known, refer to the Wattage-Wire Size Relationship table above for the voltage to be used-115 or 230 volts. From this, select a size of wire that will provide the wattage required and note the number of feet of straight wire that will be needed to make the coiled element.
Determine Close-Wound Coil Length-Having selected a suitable wire size-and knowing the lineal feet of straight wire required to make a heating element of a given wattage, refer to the Coil Winding Graph at right that applies to the size of arbor to be used. Check the point at which the vertical coordinate representing the feet of straight wire intercepts the diagonal line shown for the wire size selected. Then follow the horizontal coordinate to the left hand column and read off the inches of close-wound coil obtainable. For example, using a 1/32" arbor, 40 lineal feet of 33 gauge wire will produce 30 inches of close-wound coil.
Calculate Stretch Ratio-To determine the "Stretch Ratio" of the finished coil, divide the inches of close-wound coil into the maximum lineal inches of space allowed for the element in the device. For best results, the stretch ratio should be between 1.5-to-1 and 4-to-1. If the ratio does not fall within this recommended range, check the possibility of changing arbor size or selecting a different wire size-larger or smaller as required-and recalculate the coil element design data.