Hi Cesar,
I run a forum with over 30k threads, 187k posts, and just south of 92k members, and from my experience (good/bad), find a hosting company that specializes in hosting forums. Yes, there are companies that cater to forum hosting and forum maintenance. You should expect to pay a premium for the service, but it's well worth the seed investment, especially if you are planning to monetize the traffic long-term. Plan on isolating the forum from any other websites you might want to host on the same server (dedicated or virtual), as this will keep issues to a minimum.
Also, pick a forum software that has regular updates, patches, and access to active supporting members of that software. Going with a free forum software is not always so attractive, when issues arise. Some issues include corrupt databases, hacks, and forum membership difficulties. The company I host my forum with today even assisted me with exporting, transferring, and reconnecting my very large MySQL database.
So, hosting a Forum is just a bit different than a Wordpress website, but if you take care of the upfront investment, things will work out just fine for you. Good luck with celebrity and let us know who it is, when you can announce 
Suggestions, as you have requested:
- Forum Software: http://www.vbulletin.com
- Forum Themes: There are lots to pick from, but you might look into a custom theme for your celebrity.
- Forum AdSense: I've hand coded Adsense into the include file, to keep it simple and clean. Similar to Wordpress, there are plugins that make it easy for vbulletin ad placement too.
- Forum Hosting: Private message me and I'll make a suggestion.