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.
Images of loft furniture can be found at Loft Home, Smart Furniture, Amish Loft, Urban Loft and Loft Outfitters. Custom pieces of loft furniture can be found at Custom Made and Wood Loft Furniture.
There are many online stores that manufacture and sell hall trees with benches (e.g. Target, Sears). If you don't find one you like in a retail store, there are also furniture companies that will make custom pieces of furniture to your specifications (e.g. Pollaro, Hicks Custom Furniture).
There are a few places that one could order custom corner cabinet furniture. One could shop at hardware store such as Lowes, Home Depot, or Menards to name a few.
Make mango chutney.
"Custom-built" is typically hyphenated when used as an adjective before a noun, such as "custom-built furniture."
Information about unique furniture can be found at many places. The library in your area is a great place to start, as is local flee markets where custom built furniture can be found. Another great place is furniture stores that specialize in custom work.
A person can find a handmade wood desk chair by contacting a woodworker and having them make it, looking at furniture stores for custom furniture, or by purchasing Amish made furniture as it is all one hundred percent hand made.
One can purchase custom office furniture from Neville Johnson, Egan Reid Office and Orange Berry. It should be remembered that pieces designed for a specific place may not necessarily be suitable if one has to relocate at a later date.
One could order a custom coat tree stand from many furniture making companies. One can also look to sites which specialize in 'reclaiming' furniture which is where you take something meant for one purpose and find another purpose for it.
Fireplace surrounds can be purchased at most hardware stores and some furniture stores. It is also possible to acquire all of the materials needed to make a custom one at hardware stores.
You can order a custom end table from furniture shops that offer customization services, independent furniture makers or craftsmen who specialize in custom pieces, online platforms like Etsy that connect buyers with individual makers, or through interior design firms that can help you create a unique design and have it made by a furniture maker.