There is no full kit. This is an open source laser. The kits I have just help you source some of the custom parts, or contain parts that I can buy in bulk to save you some money. I cannot buy things like laser tubes, tube power supplies any easier than you can. The double shipments required would be risky and just add extra costs.
I just do this as a part time hobby project. I order and fabricate parts as I get time. I never take pre-orders or reservations. You need to watch the forum and subscribe to forum post to see when parts are avaialble. The parts will be is the MakerSlide Store in this section.
Is there a full list of the parts not included?
Unfortunately not. Each person completes the laser a little differently. You should read all the build instructions, drawings, schematics and buildlogs to help determine that. There is a also a list of the major components on this page. Please add to the wiki pages if you think there are items that should be listed.
Can I buy the skins and window?
I sometimes sell the skins (aluminum/HDPE composite outside surfaces) and clear window. Check the forum for when these are available.