Question From phpbb forum to full Joomla+Kunena portal

Hello, it's my first thread here and I'd really appreciate your help.

I'm running a phpbb forum with a database of around 500 users. We have gathered some new people to our team and now we're working on a full Joomla based web portal. The main problem right now is how to import the users database.

We want each user to have only one login for the website features and the forum (and maybe CB). We don't mind to lose the old threads, but we really would like to preserve the usernames, passwords, user's posting numbers and ranking. What would be the best solution for this?

Do I need to make that phpbb -> Fireboard -> Kunena method and then syncronize Kunena and Joomla databases?

Also, I've read some benchmarks about Kunena needing considerable more queries than phpbb and then being slower. We've got a pretty active forum, specially on matchdays (the forum is about a soccer club), so I'd like to know if Kunena can handle all this activity well.

Thanks in advance for the help.

I've been implementing phpBB3 importer which currently moves almost everything else than the users (user profiles are working, though). Moving users is the only huge obstacle as phpBB and Joomla have very different rules for usernames etc.. I hope that I get this issue solved in the next two or three weeks, so that I can finally publish the importer.

The importer has been developed to import huge forums with hundreds of thousands messages and they seem to be working just fine. I would not try phpBB -> FB converters as they are just hacks and they will loose a lot of information in the process. User import works partially in them, but will cause many problems when people are actually trying to log in..

Kunena 1.6 will have huge optimizations in database queries, both in efficiency and number. In optimized environments Kunena 1.5 will also be fast (see this site with 6000+ users and 25 000 messages), but in cheap hosting you may run into troubles. After all the optimizations Kunena 1.6 should scale both down (cheap hosting with a small site) and up (large boards with 500 000+ messages).