There is always the question to hard wire a kiln or use disconnectable connectors. I much prefer the latter. The main reason is I sometimes like to move kilns around the shop. And if I have a socket available at some location I can use it for more than one heating unit. Whatever your position on this issue, if you are squeamish about electricity, definitely use the socket and plug idea (by this I mean you won't have to go inside to disconnect the bare wires or hire an electrician just because you want to move something a few feet).
There is a big world out there when it comes to plugs and sockets. Here is a site that has a good set of references for the entire Nema Grade Plugs and Sockets. This isn't the only one‚ Search on the web for "Nema Plugs." Please don't forget to come back.
There are a wide variety of connectors. The connectors above are all straight blades, but there are also some heavier duty commercial wonkers, twist-locking, like what might be use at a carnival. Do some searching. My rule of thumb is to use plugs and sockets for everything up to 60 amps and everything above that use hard wire in conduit. I also use conduit on most frames up to the actual connector line which I generally use heavy duty rubber coated multi strand. Again check with your local codes about this issue as you might not have a choice: some locations you have to hard wire almost everything.