Tossing my $.02 your way ;)
The puck adapters tend to heat and then pins get soft in the plastic. Add the weight of the cable...
In our experience, the dogbone adapters are superior and less hassle.
As for Home Depot, CALL before you go. The stores cannot look up items by the part or item # online :R. Yes, it's true...they need to hire a teenager in their web department to fix that ;)
Walmart has an RV section near the automotive. Online is our normal choice, Amazon Prime, but not always the lowest price or most accurate descriptions. Heck, sometimes their pics don't match the description, but even if you report it, they don't care.
Make sure to use a heavy extension cord.