Second supplier wanted for fat-tire e-bikes — one-off capacity backup, 1,000 units

Our current e-bike manufacturer is running near capacity right now and can't guarantee the lead time we need for an upcoming order, so we're looking for a second manufacturer who can produce a one-off backup batch to cover the shortfall — not necessarily an ongoing relationship yet, though it could become one if this goes well. Product: 250W rear hub motor, 48V removable battery, hydraulic disc brakes, front and rear suspension, 7-speed, steel frame, 20" fat tires — spec close to our current line so units are interchangeable with what we already sell. Quantity: 1,000 units in this batch, as a single shipment rather than a recurring programme for now. Requirements: UL 2849 certification is mandatory for US sale, and we'd want confirmation of battery cell source and motor specifications so we can compare directly against our current supplier's units for warranty consistency. Packaging: single-unit carton suitable for container freight, unit weight and dimensions declared upfront for warehouse planning. Delivery: FOB origin, we handle ocean freight and customs through our own broker, and we need this on a tight but realistic timeline given the capacity gap we're covering. In your proposal, include: pricing per unit at this quantity, the fastest realistic lead time you can commit to, UL 2849 certificate details, and whether you'd be open to a recurring arrangement later if this first batch works out well.