Well there are some forums for this I think at MPHG you can make a topic for all kind of digital goods.
The most are also have a trusted/review topic so that would also be nice If you are doing that too, people will because of that buy way more times.
MPHG is more for game hacks and not really for digital goods if you are asking me, you can indeed try it but I do not think it will pay off.
I honestly do not know any other forum for digital good other than this forum with its own nice section.