I doubt that Home Despot will have either of those pieces in stock locally, but you should be able to order them online. I actually ordered mine from Amazon when I bought them, but when I went searching for the same pieces the only good links I could find were to HD.
I'm starting to realize now (yeah, just 3 years after I started this thread about meat smoking) that this whole thing, like most other parts of life, is a big series of compromises.
The vertical cookers (drums, WSMs, Kamado cookers, etc.) are all super efficient with fuel, will hold a steady temp for long periods with minimal fiddling, and all do a credible job of producing great 'Que, but being directly heated to varying extent are not ideal smokers.
Horizontal cookers with offset or indirect heat, are generally better
smokers, but you end up tending the fire itself more to get a steady temp, and they are not
nearly as fuel efficient as a vertical since there is so much more metal and so much of the heat gets shed by smoke's circuitous path through the pit.
Using cheaper split wood as your fuel on an indirect pit is an option to offset the fuel efficiency that may also give you superior wood smoke flavor, but you will pay for that with even more fire tending required.
Offset pellet burners are a pretty nifty idea, but you are somewhat limited to the types of wood pellets available, and the cost of the fuel is not cheap.
Burning gas in any pit gives a nice steady temp, but you will not get as much
continuous smoke, and therefore less smoke flavor in the final product, as compared to burning wood or charcoal. And they aren't as much fun since you don't get to indulge your pyromania. Same thing goes, maybe to an even greater extent, for electric smokers.
I guess we all just get to pick what amount of effort we want to make and how picky we are going to be about the end product.