1 Ball Valve (Not sure what size)
2 Pipes w/ nipples (Not sure what size)
Stainless Steel Screws and nuts (Not sure what size)
1 Weber rack to start
*unless you plan on using the step bit ALOT, you might save some of your gift card money and hit up a Harbor Freight store if you have one close enough to justify the trip.
*Some Weber replacement grills have the "flip up" sides...IMO don't spend any extra for this feature.
*As mentioned already, buy beer.
*Save some coin...don't buy the expanded metal (for the basket) from anywhere but your local welding shop...most shops have a scrap/remnant stash that you can buy steel by the pound...often narrow strips good enough for baskets can be found. No worries if it is rusty.
*You might pick up some paint while at the store.
*Be sure to calibrate the thermometer and be gentle when tightening the mounting nut so you don't mess up the calibration.
*If you use bolts to make your basket, consider some larger sized fender washers that will work with the expanded metal grating hole dimensions.
*If you find yourself at a Harbor Freight, take a peek at their cheapest little red dolly...$18 or so. I use these on my smokers...simply mark the barrel to accept some U-bolts that you will use to tie the side tubes of the dolly to the middle of the barrel. If you do this mod, be mindful of your intake holes so you don't accidentally block them with the dolly.
*I buy the cheap hardware...not stainless. I doubt any of us ever "disassemble" our smokers...so rusted up bolts and nuts are not a problem to worry about. If your shop is well stocked, you might have some muriatic acid (concrete cleaner)...if so, (and you have not had too much beer yet) carefully pour about a 1/2" into a small plastic container and carefully place your zinc coated hardware into the acid...it will dissolve the finish. Just buy the stainless hardware if you have never worked with muriatic acid before.
*Will you be needing concrete blocks to sit it on?
*Oh...and buy beer.