Hi thecountofzero,
The green sleep is a bit firmer… When I was shopping the team at tmasc.ca first started with do we think we prefer firmer or softer. We said firmer, so that put us on the green sleep track. It’s all about PPP 
I know all about the tighter fit of the top, and yes it does change the feel. (I was testing all sorts of things, and wasn’t zipping up the mattress case each time to avoid very frequent wear on the zipper. Anyhow, once I found a winning combo I zipped it all up. Of course, that changed the feel of the very thing I had been working on trying to change, and had to change again) 
The 3" wool topper is the sleeptek classic 2000.
http://www.tmasc.ca/wool-mattress-toppers/sleeptek-classic-2000-wool-topper.html
My review of it is here:
https://forum.mattressunderground.com/t/sleeptek-classic-2000-3-wool-topper-review
Yes, the visalo mattress protector is deep enough to cover the mattress and topper, and that is how I do it note: the visalo I got is from tmasc.ca, and looks identical to their pictures. I’ve seen other websites selling it, but their pictures look different. I don’t know why.
(If you’ve not guessed, I live in a city with tmasc, and have been delighted with them and am a return shopper there - extremely knowledgable and I’ve had great service).
For the mattress case / quilt… I’m getting it from Sleepys.ca. It took me a while to find it. It’s a plain 100% organic cotton 4-way stretch knit… Definitely nothing ‘fancy’ in design, but was what I wanted. I originally got it as a topper cover, and went back to get it as a mattress case also. I’ve been getting my DIY stuff from Sleepys.ca, and they have been wonderful also. Tmasc.ca does less DIY stuff. It would be total overkill, but could be used to cover individual pieces of latex within a bed. If you went that route, ask to get the organic cotton on all sides (many topper covers come with a different material on the bottom). Of course, this is all Canadian, and while I’m sure you can order from them, there may be easier USA options. To give some idea on price, I was $160 for a cover for a 3" layer twinxl. It’d be about $320 for a cover for a 3" king plate of foam. So for a queen with 3 3" layers, you’d be in the $750 price range (ahhh yes, how costs add up for good fabrics).
Note that the topper cover I got is a far, far heavier material than the material surrounding the latex inside a mattress I have. So it’s hardly a direct comparison. Also, the material surrounding the latex I have don’t have zippers, it’s sewn in place. You can now see a picture here:https://forum.mattressunderground.com/t/anyone-experimented-with-diy-zoning-like-flobeds-vzone-obasan-green-sleep-europe
If I were looking for organic cotton for latex layers, and based on what I know, I’d do the following
- Ask spindle to do it. They clearly have a sister company that can, and already have access to organic cotton,
- Same as #1
- Same as #2
- There’s someone that posts here from diynaturalbedding or some such. I think their website is diynaturalbedding.com. I’ve never shopped there, but based on their website it looks like the kind of place I’d shop and get this kind of thing.
- Start calling around…