Hello, I do not believe you can find "new" engine components for a 1991 Accord, unfortunately. Everything out there will have to be remanufactured at best, or used.
RepairPal Certified shops can diagnose and repair your 1991 Honda Accord. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
From a practicality stand point it may be in your best interest just to purchase another vehicle.