Hi shift_47_
The better online latex component suppliers I’m aware of are listed in post #4 here and there is also a list of suppliers that ship across Canada in post #21 here.
There is also a list of the better manufacturers and retailers I’m aware of in the Calgary area in post #2 here.
I don’t keep a record of the individual products that are sold through the many retailers or manufacturers that are listed in the hundreds of lists throughout the forum (it would be more than any one person could keep up with in a constantly changing market) so I’m not sure which of these make a zoned topper with the zoning pattern you are looking for or make custom size toppers off the top of my head so you may need to check their sites or call and talk with them to see which of them either sell or can make a topper that fits your criteria.
Phoenix