QR's worries about .exe are somewhat overblown... most people that are going to be getting mods for SE4 are not the kind that are that superstitious about computers.
Most people can handle RARs, once you tell them to get a non-WinZip archive utility. Change must be started at some point... I personally plan on releasing very few files in zip format unless they are very small (a few KBs, for example).