No worry about having 8GB and 256GB SSD storage on the new M1 iMac 24"
The new M1 iMac are coming next month. For majority of users the entry level S$ 1,849/- will be more than enough to do your work. There is no need to upgrade additional for 16GB ram or 512GB SSD storage. Since Apple soldered all the chips into the motherboard what you need to spend on is an external Thunderbolt4 SSD drive or a cheaper USBC SSD Drive, both of these external drives will be very fast for your work. The reason is, if and when the motherboard is faulty Apple can replace the motherboard, you do not have to worry about your data since it is stored outside of the iMac. So the Apple 256GB SSD should have only the Mac OS X and your software applications. If you have a large Photos library you should put this library in the external SSD Drives (your Photo library need not reside in the internal 256GB SSD storage).