What do I need to build a handmade kilt

[The Wizard of BC]

Once your copy of TAoK arrives you will find a pretty good list of the materials and tools needed.

But here are some comments -

The Tartan "Spirit of Bruce" is not one listed with "The Scottish Register of Tartan". Nor on the"Scottish Tartans Authority".
It appears to be an unlisted, proprietary design out of Pakistan. Hence why your first kilt was made from Synthetic yet sold as wool.
So you may be looking at a custom run of fabric. Please, please check with your chosen weaver for pricing and minimum yardage requirements before committing to this project.

How much fabric you will need depends on five factors.

1) The circumference around your hips and buttocks.

Obviously the larger someone is, the more fabric that will be needed.
Most kilt makers use a hip circumference of 45 inches as the difference between ordering 4 yards and 5 yards of double-width fabric.

2) How you plan to fold the fabric into pleats.

Knife pleats require more fabric than box pleats.

3) How you wish the Tartan pattern to be displayed in the pleats.

If you choose to have the pattern display the same element down each pleat (Display to Stripe) you will need one full sett for each pleat.
If you choose to have the pattern display the entire Sett (Display to Sett) you will need about 1 full sett more for every 6-8 pleats.

4) The Size of the Sett of your fabric.

An average Sett size can be between 6.5 and 7.25 inches.
Larger Setts will need more fabric.

5) Waste

Please plan approx 10-15% waste.
Things like lining up the aprons and doing the mid kilt join can use up more fabric than you may think.

In addition to the materials and tools list you have add a strip of Broadcloth for the stabilizer band.
Find a source for good quality hair canvas (also called chest canvas) for the interfacing.

If you have not sewn a lot you may want to practice stitching. The idea of hand stitching a kilt is that there should be no visible stitches on the outside of the kilt.
The mark of a good kilt sewer is one who can align the tartan elements perfectly.
Both of these skills take practice.