赞比亚采购需求：办公椅，办公桌，办公沙发，文件柜，学校家具，培训家具

I'm looking for three items: an executive adjustable swivel chair, a large executive desk, and a low-back visitor chair. The chair should feature a sleek design with a durable outer material. The desk needs to be spacious, with specific dimensions and a quality finish for a professional look. The visitor chair should be upholstered in black PU leather for a comfortable yet stylish appeal. Please provide product details, including any specifications or options available for customization. Looking forward to your prompt response!