Upholstered banquette seats are available at Overstock.com, BallardDesigns.com and Houzz.com. These web sites offer a variety of different upholstered banquette designs, colors and price ranges
Overstock.com has the least variety of style choices and colors of banquette seats, but the prices are reasonable, starting at $426.14 as of November 2015.
Ballard Designs has an extensive variety of customizable banquette styles and colors, including corner units. These units are available in different sizes and also offer built-in storage.
Houzz.com has modern-looking styles of banquette styles. Houzz.com also offers customization with some of its banquettes. Houzz.com is more expensive; many of its products average over $1,000.