Hi @trasek
A good question. Currently, there is no way to add the ACF fields to a gravity form. This is a limitation of the plugin.
As for the file uploading… perhaps the solution would be to use a more basic file uploader.
I am currently working on one and I will be releasing it into the core soon.
Perhaps you would like to do some testing with it? I’ll attach it to this comment so you can try it out!