Thanks for the replies guys. Happy to see that it also sparked some interesting discussions.
I decided to go with KVS in the end. But as feared/predicted I already ran into technical issues regarding uploading files, and it seems that KVS support is ran by a single guy.
Would be wholesome if someone of you guys helped me get out of the starting blocks a little. Drop me a message if you want to help me out a bit

- I will put your link on my frontpage for the next 3 months (as long as you arent serving malicious adds)
Best regards