We have experience working with most established Joomla extensions.  If an extension does not have a Joomla 3.x version, we will install a similar extension and manually migrate your existing data into it.  Below is a quick list of extensions we work with the most often.  Items with an asterick (*) next to them are ones we often substitute:

Blogs, CCK, and Directories: K2, ZOO, EasyBlog, SOBI2*, Mosets Tree, DOCman, PhocaDownload

User Interaction: RSForms Pro, Chronoforms, Blue Flame Forms*, JReviews, JComments, JNews, Kunena Forum, Agora Forum*

Slideshow/Galleries: PhocaGallery, FrontPage Slideshow, RokStories, RokSprocket, Widgetkit, JA Slideshow

Events/Calendar: JEvents, GCalendar, DT Register, JCal Pro, MijoEvents, Simple Calendar

eCommerce Shopping Carts: Virtuemart*, AceShop, MijoShop, Simple Caddy, HikaShop, RedShop