Fire Mountain Gems & Beads: http://www.firemountaingems.com
Source for Japanese and Czech beads and some copper-core wire. I recommend the Zebra brand colored copper-core wires. Avoid the silver and gold.
Shipwreck Beads: http://www.shipwreckbeads.com
Source for Czech and Vintage beads.
Source for copper-core wire.
Source for copper-core wire and bead spinners.
Bead spinner sources:
Spin-N-Bead Junior (Amazon US): https://tinyurl.com/ycuhf4zr
Spin-N-Bead Standard (Amazon US): https://tinyurl.com/y7yj8uqw
Spin-N-Bead Junior (Amazon UK): https://tinyurl.com/y9y7ofpz
Spin-N-Bead Standard (Amazon UK): https://tinyurl.com/ybuldmmc
Check local craft and hardware stores first as you may be able to find better prices on the below items. Bulk items generally are cheaper to purchase online.
Acrylic Water: https://tinyurl.com/y7ag2q6u
Bulk Embroidery Floss: https://tinyurl.com/y7ct77v4
12-gauge steel wire: https://tinyurl.com/yd3tuvz5
Bulk floral tape: https://tinyurl.com/yagn2635
Multi-color floral tape: https://tinyurl.com/ycalan2j
Bulk Brown floral tape: https://tinyurl.com/y8bc87vk