Hello.
I would REALLY appritiate any help from SMF team, or someone that hosts a forum of a larger size today..
Anything will help.. how many users you have, visits / day and bandwidth usage / month etc etc..
diskspace and anything else that might help me scout out the right host for myself...
Try a search for 'bandwidth posts host' or similar, but here are two topics to start you off:
http://www.simplemachines.org/community/index.php?topic=11053.0
http://www.simplemachines.org/community/index.php?topic=22032.0