Advice Needed Suggestions on what to do with SeoNinja.club

1st idea and the 2nd much better mate, making a forum will cost you alot of shit and at the end it's almost the same as a blog, the only thing of building seoforums is thazt you will get more money on upgrades etc...
while on the blog all your earnings you will get is from ads.
you can try your luck and if both ideas didn't work, just sell it.
good luck on your project.