Found XenForo and it seems exactly what i'm looking at for my upgrade path. Planning on taking my data (Users/passwords/forum layout/threads/posts/possibly polls and attachments) and going to ipb but this software is very interesting.
Reading some of the threads here - see the converter is for 3.7/3.8? What would be my import success going from 3.5 to XenForo?
Thanks for the help and keep up the great work!