104 Pcs 40 cm Stainless Steel Spring Wire Music Wire, 12 Different Straight Full Hard Spring Steel Wire, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2 mm, 3 mm
https://a.co/d/e2MItwl
White Polystyrene Flexible Plastic Board Sheet 8" x 10" (.020 Thick) Styrene Sheet, Ideal for Modeling Projects, Displays, Plastic Sheets for Crafts, Styrene Sheets Durable Plastic Sheet (5-Pack)
https://a.co/d/eVu85lu
Plastruct Plastic Weld w/applicator 2oz Bottle
https://a.co/d/0PyxNWf
Plus some link bars for the triangulated top links, or a single one for a 3-link setup. I would probably go 4 myself just for the added durability. Some short links for the connection from the rockers to the axles, shocks, a bit of hardware and you're set.