Everything above is a good option for SD storage.
I'll add another vote for the Ultimate1541, mainly for two reasons.
1) It is easily the most compatible option out of all of the floppy drive emulators.
2) It is in active development, with new (unexpected) features still being rolled out on a continual basis. For example, the most recent update was late May, 2020.
The User Interface takes a bit of getting used to IMO at the beginning, but eventually feels second nature. € 115 excl tax isn't a cheap device, no doubt (+ tax/shipping). But I'll go so far as to say I think this is one the absolute best peripherals for the C64 ever made. You could spend
months just trying to understand and exploit all of the features.
Turbo Chameleon is much more expensive, but you do get a lot of additional features there, too. For me personally, I mainly use it for the accelerator, which isn't very often. Development on the TC seems to be in perpetual beta status but what it offers today seems pretty solid. I think there is one guy out there with a Patreon devoted to building more features for it if anyone has specific demands. The TC is way more than just a C64 image loader, though. It's pretty much a Mist in cartridge form, and can even run different cores. It's crazy.
SD2IEC is hands down the least expensive option out of everything and a nice place to get started. But I've personally avoided it (rightly or wrongly) due to the compatibility issues I've read about. I don't think they are major at all, though. I have a couple friends who use the SD2IEC as a primary drive, and when they run into issues they whoop out an original 1541 with actual disks as a fallback.
Wiki
Expect almost all software that runs in VICE without exact floppy emulation to work (at least in D64 mode)
I'd read the various feature sets and see which ones you think realistically appeal to you most. There's a lot to go through. (And don't forget the Backbit, too. It costs more than the SD2IEC, but is less than the other options mentioned.)