Good idea

Buy nothing. I'd need a USB hub for the iPad too. And I don't know if it'll show more then one storage device at the same time.

I could use the external SSD I have, but it has SWAP on it.

Is the Pi 4 in stock anywhere yet? The 4 GB one. It still is on the UK site, that's 12 day shipping.

I think new AMD CPUs are coming out this month, but that'll cost around $300, for the 8 core 16 thread one.

The premium shipping is 2-3 days. How much is that? Around $21, and the cheaper shipping is around $8. Not really worth it, the 12 day shipping should be free.

The new AMD CPUs come out on the 7th. Maybe I'll have enough money. Unless I spend it all.