After two days of testing several different software (Drupal, Geeklog, Joomla, Joomla 1.5 and Mambo Open Source) I have decided to proceed with Joomla 1.5. I had difficulties with inner linking, because Joomla 1.4 added index.php into links, which broke them. Here's an example:

Link: http://www.kirnu.com/component/content/article/5-kirnu/1-kirnu-under-construction was transfered to

Link: http://www.kirnu.com/index.php/component/content/article/5-kirnu/1-kirnu-under-construction so the extra index.php/ broke the linking.

The problem got fixed from Joomla 1.5 admin interface: Global Configuration --> SEO Settings --> Use Apache mod_rewrite and choosing: Yes.