A couple of tips:
Buy a good electric stapler , or pneumatic if you have a compressor.
Any walk-in fabric store will sell you fractions of a yard, like 2 1/3, not sure about on line.
If you use phifertex mesh, staple it first, to keep the seam just under the bottom curve of the bolster. Buy a yard and piece it.
Phifertex doesn't stretch like pleated vinyl. Practice on some scrap to get your hand and machine tension right, or you will end up with a banana shaped piece, which will pucker when you try to staple it straight.
If you have a 90* angle, start stapling right in the center, and work towards both ends.
Use flat vinyl for end caps.
Buy pre-made welting, if you are using it, and the only sewing on a bolster with grommets instead of mesh is the end caps, which can be done on most home machines. Remove the batting from the pleat where the end cap is sewn.