I'd go for a 2011 13" MacBook Pro for the following reasons:
1. No GPU issues (because there is no discrete GPU).
2. It can run Snow Leopard - and boy, SL is fast on one of those! - all the way up to Catalina (with patches; no idea about Big Sur).
3. It has "all the ports" including FireWire and Thunderbolt.
The lack of USB 3.0 is a nuisance but can be overcome with a Thunderbolt to USB 3.0 adapter.
Latecomer to this discussion but I was curious about the adapter because of course I own a 2011 13" MBP (and also a 2011 i5 MBA w/ Thunderbolt) but the item in your link is out of stock. Other vendors stock it but the price is eye-watering. Why is it so expensive? The scarcity?