Upgrade Magento: 1.4.0.1 to 1.5.0.1

Hello! We have a Magento store. It is version 1.4.0.1. We need to upgrade it to the most recent stable release version, 1.5.0.1. We can duplicate the store to another directory on our site so you can upgrade and test it safely. We have these extensions, which should still be compatible with the newest version of Magento: Biebersdorf_CustomerOrderComment Fooman_GoogleAnalyticsPlus Fooman_Speedster IKT_OrderExport Locale_Mage_community_de_DE Locale_Mage_community_es_ES Locale_Mage_community_fr_FR Locale_Mage_community_it_IT Locale_Mage_community_pt_BR Locale_Mage_community_ru_RU Luxe_Bestsellers Myown_Bestseller Pw_Multipletablerates RicoNeitzel_VertNav Zopim_Live_Chat magento_easy_tabs Please bid on this project only if you are sure you can upgrade Magento. I strongly prefer someone who has upgraded Magento before. Please let me know the cost and the time required. Thank you very much!