SEMROC BNC-80K
BMS BNC80K (scroll down a little to find it)
Shipping is included in Semroc's prices so the two are very similar in cost.
You will need a single 21.6" length of BT-80 (or two shorter lengths and a coupler like they do in the kit), a pair of CR50-80 centering rings, 1/8" balsa stock, and some BT-50 for a motor mount. All can be purchased from most vendors including the same places I've linked nosecones.
Use elastic from the sewing section of your local department store, and pull a chute off another rocket unless you want to buy new kevlar, new chutes, etc.
BTW, SEMROC has everything needed to make a clone except decals and laser cut fins listed on one page. They do have plain fin stock.
Phoenix parts list