Contact the stores that sell those items and ask who their wholesaler is, or search for a wider range of trade shows.

Is there a market for this type of clothing? If not, move on to something else. If so, and if it is truly a niche worth pursuing, you may need to go to a manufacturer and design your own line of private-label items.

Then you can become the wholesaler to retail outlets or a direct retailer with a unique private-label brand.

All the best.
Brad Sugars