Custom black desks can be purchased from Custom Made, eBay, 1st Dibs, Etsy, The Container Store, Pinterest, Ambience Dore, Ambient Weather, and Amazon.
One can purchase a black corner desk from stores like Staples, Target, and Ikea. One could also purchase such a desk online from Overstock, Wayfair, and Cymax.
There are many places where one could purchase a craft desk. The best places where one can purchase a craft desk at furniture stores like Levins or Wayside.
You can design your own computer desk at computer-desk-assemble.com Also you can learn to set up your own printer.
There are many places where one could purchase a portable lap desk. The best places to purchase a portable lap desk would be places like Amazon or places like Walmart.
One could purchase a modular desk from a local furniture store or warehouse, Costco, Ballarddesigns, Houzz, Tesco, Amazon, Westelm, Tomshardware and Target.
The advantage of a custom desk is that its made just the way you want it. It has everything you need and could possibly want.
You could probably get a carpenter to make you a custom desk. Or you might luck out if you have a furniture manufacturer near by, but generally, stores don't offer custom desks.
If you want a computer desk that is truly custom you will need to contact a woodworker or specialty company. If you would be happy with something put together in a unique way out of modules you could go to an office supply store to get them.
My suggestion would be to look at any store that sells furniture, such as a desk. A place to look into would be Office Depot.
One can purchase a Step2 Art Master Activity Desk in many places such as the local art store. One can also purchase such a good online on websites such as Amazon.
Amazon is a very good place to find accessories for a desk. They carry many different brands in a vast range of quality and price. Pretty much any accessory you could want to purchase for your desk can be found on Amazon.
For a custom wooden desk, the best place would be to look locally for anyone who does woodwork. They would build the desk to your exact specifications, color, size, whatever you want.