Why not just merge the database to the new software,most are able to be merged in some way....
If your thinking about new software,i suggest looking at SMF (http://www.simplemachines.org/community) one of the BEST FREE software out there..
The best S/W of all in my opinion is VBB,but we would all have to chip in some $$ and send it to matt before he would even think of VBB ($80 license (Last i knew,may have gone up))