Here are links to several companies that can provide you with rod building materials and kits

SaraBella Fishing Company   https://www.sarabellafishing.com/

Hook and Hackle   http://www.hookhack.com/html/rodbuldingkits.html

Mud Hole  https://www.mudhole.com/

Custom Fly Rod Crafters http://www.flyrodcrafters.com/

Proof Fly Fishing  https://www.proofflyfishing.com/

Anglers Workshop   http://www.anglersworkshop.com/

You will need

A blank

A guide set to match your blank (use the rule of thumb of 1 guide per foot plus 1, this includes your Stripping Guide but NOT your Tip Top)

A tiptop to match your blank

A grip (the cork)

A reel seat

A Hook Keeper

Thread

5 minute epoxy

Finish or thread epoxy

A rod sock

A rod tube