Looking for Something?
William Duffield, on the Cohansey
When perusing their online catalog for veneers, select "flitch". Purpleheart is $1.40 per square foot. You'll have to look for the bloodwood yourself. Quoting from their catalog: "All of our Flitch Veneers are Sold by the square foot, we cannot guarantee specific sizes, however if you require a specific size, please note the size in the Special Instructions box during checkout, we will fill your size requirements as close as possible."
Note that demanding specific sizes is always a false economy when it comes to veneer. You are setting yourself up for failure. You are better off buying it oversize, based on the sizes of the logs the manufacturers started with, and selecting figure and matching grain and cutting it yourself, than asking the seller to select and cut it to size for you. You end up with a better quality finished product, and you can use the offcuts later for other projects, or for repairs. Anyone selling veneer will charge you labor for cutting it, and also for whatever offcuts are left on their shop floor. They can't sell the waste, but you can use it.
Also, if you do eBay, there are lots of people who sell veneers there, often at very reasonable prices, but you have to spend a lot of time searching for what you need, so if you have a deadline, these sellers may also be a false economy.