Wix vs Images

Hi Guys

I want to achieve the following: Users can make/upload a profile picture.

The problem: When there a lot of users (> 1000), the storage limit of 25 GB will soon be reached. That’s why I was looking for alternatives:

Alternative 1:
Standard S3 Amazon Storage.

Problem: Since we can not install the SDK (require doesnt work), computing an authentification key is not (really) possible.

Alternative 2:
Dropbox.

Problem: I can use the REST API very easily, but the file access is limited to a few 1000 accesses per 24 hours. I want to be sure, that this is not a problem, so I want to cache the images on wix (e.g. hold the 1000 most recently accessed images). The problem is, that it’s not possible to actually store the images, but only the URL’s, which will still trigger a download on via the REST API and thus increment the counter.

Alternative 3:
?

Do you see another way to solve this problem?

It would be nice to get feedback.

Thanks in advance,
Sandro