Migration from Xoops to Drupal or Joomla for an existing Greek language website / forum

We own a website forum since 2005 and we want to make some changes. First of all the site is in Greek language and the new site will be at Greek language. The present website/forum has been made with Xoops and we want to migrate to the newer version on Drupal. We can check joomla too but we like more Drupal. What we want: 1) Any action a present user has at our site must be able to have at the new site too. Of course these must be upgrade to the most new from the aspect of functionality , security and aesthetics. For example 1) we want to trouble the existing members the less we can..so if we can to avoid make them do a new register, we will prefer that. 2) users can download files from our site and we want them to be at the new site too. 3) the topics of forum must remain at the new site too. 4) Statistics, the same… 5) Live chat. We want something more suitable for young people. Something suitable for a target group of 17 – 40 ages. 6) We want captcha for sign in and for posting new articles at user. We like to hear suggestions on this.. What new we want to have. -------------------- 1) Fresh style. You can take a look at [login to view URL] [login to view URL] to take an idea. 2) New and bigger logo at flash . 3) guide of searching institutes of vocational training in Greece. 4) Ability of backup of site on our own. 5) how to sign-in… we like the pop up window from http://www.papaki.gr. 6) more movement to make the site more “alive”. 7) rss news to users. 8) twitter news. 9)newsletter at users when the fill in a form with their email. 10) tag gloud. 11) ability of users to comment the site something like a version cloud. For example “hey I sigh in today and I like the site a lot!!!” 12) the site must give me the ability to manage advertisements with a suitable software. The clients must have the ability to see their statistics and upload their ads on their own at a variety of options. For example flash, jpg at dimensions of their prefer and goes on.. 13) ability to users to log in and use the site via smartphones android, iphone etc..so we need a web mobile version of the site too. That’s for now as a first idea. If you contact with us we can talk about via email of via facebook. The link of our site is [login to view URL] The major of our site is “vocational training institutes in Greece at the fild of IT technologies” It is a site forum for people who study computers at variety of speciality. Thanks for reading this and we our looking forward to hear from you. We apologize for our English writing and we hope to make ourselves understood : )