>>> connected with my iPhone apps
That changes things a little.. In that case I personally would stay away from freeforums. They use proprietary software, which means limited scope for the future (you knew there had to be a catch somewhere
I'd stick with a well known forum software package such as SMF, phpBB or vBulletin that allow independent backups and portability
You DO have to think about the future... during the early startup life of this site I went through various hosts as it grew, Ive only remained with my present hosts so long because they are flexible and allow bespoke arrangements. But you need software where you are going to be able to backup and port either to a new host or even port between software packages (Ive done that a few times too). You dont want the prospect of all the data being lost if you wish to move or update your forum software.
Whilst I run a web server from my PC - its more of a 'plaything' and used for things like testing... and despite having 2.5Mbps upstream, its not something I consider for much more than personal use. You need the box to be on 24/7 and your connection to be up 24/7 - not to mention how it will impact your bandwidth. Everytime someone connects to your forum, it will be using your bandwidth.. and conversely if you are doing something that is using up your bandwidth (such as downloading large files) then the forums will run very slow (yes I know its possible to use tools such as netlimiter to prioritise) but IMO, I dont think this is the best action for 7LM. - It may be fine for a little while, but its only putting off the inevitable.
IMHO you have 2 options
1) Get your own hosting that allows an SQL database (there are some cheap packages around that will provide you with one SQL database).
2) I dont know what your current hosts provide you with.. but Im assuming you just have FTP access for http and no Control Panel access. They will simply need to provide you with an SQL database (for a forum) and create an SQL user (for the database username). This wont be a big deal for them if they are commercial hosts and will only take them 2 mins to sort out
In either instance you then need to choose which forum software you wish to use (such as SMF/phpBB etc). Once that has been uploaded you will then need the following info from your hosts get the forum software up and running:-