Ukraine can hold out until the West gets its production (of all systems) back in line with worldwide requirements. Russia has already received the 1M shells, and they are of poor quality. But even at a 50% failure rate, they've had an impact.

The F-16 is actually the best choice. There are multiple users worldwide, so lots of training facilities, lots of spare parts depots, and almost every NATO weapon is qualified on it. The Gripen would be great if it wasn't needed for a few years; the production rate is too slow to fulfill Ukraine's needs and the Swedes have no desire to send stock from their own air force. Can't blame them really. They've been cutting back on their military like the rest of Western Europe for decades.