Quick question on uploading GameCube discs....

Apologies if this is a silly question, but I've never distributed my own personal rip of a disc before and want to be sure I'm doing this right: Am I supposed to convert to the .nkit.iso format myself and upload that, or do you guys prefer to receive the 1:1 ISO for easy verification, and then convert it yourselves before hosting it? On my end, bandwidth/upload speed/etc. isn't a concern, and I'm big on preservation, so I'm a little wary about distributing a modified/compressed rip, but I can surely handle the NKit conversion if that's what you'd want. Furthermore, if I do convert it myself, is there any extra data I'd need to include so that others can use NKit to convert it back to a 1:1 ISO? And one smaller question while I'm at it, would .zip or .7zip be preferred? Thanks in advance for any advice!

Also, for anyone curious, the disc in question is the US-region Game Boy Player Start-up Disc v1.02. Nothing too terribly interesting, but I'm happy to give back whatever I can! I finally ripped my personal GC/Wii collection over the last few days, and have been browsing around here grabbing games that I lost/had stolen/never owned in the first place (thanks a lot to all hosts and contributors! :) ), and coincidentally noticed the 1.03 GBPlayer in the recent uploads. I remember getting mine pretty early on, so just for fun I ripped my own, and lo and behold, it's the 1.02 version you need.