Look up 'knife making' supplies using your favorite search engine. Get an appropriate blank that closest matches your dimensional and metallurgical requirements and either grind it yourself or have a someone who does such work do it for you.

There are some custom knife makers who accept work in the form of drawings and specifications. They may consent to using a blank you provide, or not. They can often help determine what you want and offer suggestions on relatively arcane subjects like selection of the steel, heat treating and grind angles. But their expertise and skills seldom come cheap.

If you know what you want you may be able to save money by finding a more generalized metal working shop.

If you are determined a thick blank can be ground on bench stones by hand. It really doesn't take that much effort if you use really course stones to rough the shape and work your way to finer stones. I have also seen bench tools like sanding discs and bench grinders used. More than one home smith has used a belt sander. Power tools save time and effort but they also make temperature control more critical.