Mac options within your budget...
Mac Studio with the M1 Max chip (US$2,000)CPU: 10 cores
GPU: 24 cores
Memory: 32GB
Storage: 512GB
I used this computer for two weeks recently. I was impressed enough that I'm having one made to order that meets my own needs. This is easily the most powerful computer of the options. I think that it makes sense
if you want the power (it has quite a bit more than you need for 1080p video), you're satisfied with the colour accuracy of your LG monitor, and a Mac Studio is mobile enough for your needs (2.7kg; 9.5cm x 19.7cm x 19.7cm).
14" MacBook Pro with the M1 Pro chip ($2,000)CPU: 8 cores
GPU: 14 cores
Memory: 16GB
Storage: 512GB
I would choose this over the Mac Studio if you need more mobility than the Mac Studio offers, and the 14" is one option if you're dissatisfied with the colour accuracy of the LG monitor. You could also decide that the Retina XDR display with ProMotion in itself is desirable. Based on what I've read about this laptop, and given your current requirements, I would not worry about heat and throttling.
13" MacBook Pro with the M1 chip ($1700)CPU: 8 cores
GPU: 8 cores
Memory: 16GB
Storage: 512GB
I have no doubt that the M1 chip with 16GB of memory will meet your current needs (more on this below). Otherwise, similar considerations as the 14" MacBook Pro above, but $300 less expensive. However, note that it has a standard LCD Retina display. Also, it raises the question of how you feel about editing on a 13" laptop screen. You
could split editing chores between the laptop screen and your LG monitor (also true of the 14" MacBook).
Mac mini with the M1 chip ($1100)CPU: 8 cores
GPU: 8 cores
Memory: 16GB
Storage: 512GB
The mini has the same specs as the 13" MacBook Pro, but at a more attractive price because it doesn't include a Retina display, keyboard and trackpad. Leaves room, if needed, to purchase a new monitor, or simply to save some money.
Speaking of monitors, you should include in your budget the cost of monitor calibration hardware and software. Many people use X-Rite's i1Display Pro, but Spyder is also popular.
In your initial post, you expressed concern about the basic M1 chip used in the 13" MacBook Pro and the Mac mini. When these computers were released, the reaction was uniformly favourable. If you search this forum, you'll find a long discussion thread about them. The thread includes links to several reviews.
I'm linking Mark Spencer's video below. Spencer and Steve Martin run
Ripple Training, and Spencer is probably the foremost authority on Apple Motion. Soon after these computers were released, he tested the 13" MacBook Pro with 8GB of memory. I think that 16GB of memory would have improved performance of the 13" MacBook significantly beyond what it already showed. Since Spencer made his video, both Final Cut and DaVinci Resolve have been further optimised for the M1 chips.
If you are considering the 13" MacBook or Mac mini, it's worth noting that Apple is expected to launch the M2 chip before the end of the year. It's
possible that it could announce M2 updates of these computers at its annual WWDC on June 6, although I think that we're more likely to see the new Mac Pro at that event.
Mark Spencer video - if I recall, he was on vacation in Central America at the time