Move from Joomla to WordPress

Hello folks:
Nice to discover this forum. All of our current sites are in Joomla but one of our designers is a big fan of WordPress and has been urging us to switch to WordPress. We have finalized our two sites for this conversion: http://toyota-dealer.org and http://dubai-car-dealer.com. Now my questions are:
1. Is there an automated tool that will allow us to convert our Joomla articles into Blog post
2. Since menu strucutre is huge. We would also want that to be covnerted automaticall
3. Is SEO better than Joomla? Can we get SEF URLs out of the box?

These are just some of the questions. Last year we had converted one of our site from Joomla to Drupal but we were only able to transfer less than 5% of our content so in the end decided to move the site back to Joomla. This cost our ranking in Google and this particular site never recovered. Thie time around we want to do the conversion offline and then take it online once the offline site works. Any feedback will be greatly appreciated.