the error is because you are getting dependency conflicts. This usually happens when manually installing packages because its up to you to keep track of dependencies. From the page that i linked those methods involve creating a list of all the dependencies that need to be installed with the package, downloading them from another machine, and then installing them on the original one. Ive never tried them but i would assume it could help your issue.
also i dont think you should be installing busy box, thats usually for stripped down systems. The conflict is from trying to replace a core binary with one from busybox.
also just found this https://askubuntu.com/questions/503397/how-do-i-install-wpa-supplicant-on-an-offline-server