https://www.channelclassics.com/shop/?filter_format-type=sacd
https://www.highdeftapetransfers.com/
and so many more. But not all of the above are digital download. Some of them are physical sacd that you will need to rip yourself, so if you are looking for purely only digital download sacd you will be limited in options
Personally think the better approach is to instead find the music you actually want on dsd through some place like https://sa-cd.net/ or https://www.hraudio.net/ and then look where to buy it. Because don’t buy dsd just because it’s dsd, make sure it’s actually good music first. There are times where dsd versions just aren’t as good as others due to mastering, performance, or just different sonic focuses that you don’t agree with. Labels and smaller stores are also typically limited in selection so looking for music first then finding out where to buy it 2nd is what I would personally suggest doing. DSD is great don’t get me wrong, but also don’t make it your utmost priority to find everything in the format
Also places that sell used music are your friend as well, because there’s a fair amount of dsd that isn’t released anymore or was limited production, so your only chances for some recordings will be scouring the internet for a used copy (but try not to get gouged, can happen easily if you aren’t careful)
If you are entirely anal about things, and your dac simply does sound a whole lot better being fed dsd, you can always upsample (either on the fly or permanently) to dsd and that can help some with some tracks on some dacs. But really I wouldn’t suggest doing this unless you have a very specifically dsd focused dac that only sounds good in dsd (don’t think the micro bl falls into this category)