That can DEFINATELY be done! If what you mean is if you can change the forums page to www.example.com/forums, and use www.example.com as a home page, it can be done. If you would like me to go into further detail, please PM me.
In My opinion, IP.Board is the best you can get with forum boards.
--It has TONS of add-ons from the Marketplace, IP.Board also has the best price options I have seen anywhere.
--IP.Board, again, is a really nice, easy to use, stable forum board.
--I am not sure what you mean with freeware or a full paid software, if you are referring to another board, you should probably get a license (paid) to have full technical support, and so your site will not get shut down.
--IP.Board again, (in my opinion) because they have a lot of FREE applications, skins, etc. It is a more widely known Forum Board. It is EXTREMELY EASY to use for Administrators.
--I use IP.Board because it is on almost every forum board I am ever on. It is easy to use, it has GREAT pricing plans (as low as $5 a month!)
--I plan on STAYING with IP.Board because I am accustomed to it and am becoming really good with it.