Add-ons Needed

We are considering renewing our subscription but have three questions. (1) Our site is a Joomla 2.5.16. If we download the component for 2.5/3.0 will it work both now and when we eventually update the site to 3.something? (2) I'm listing our info below. It has been sometime since updating and I'm wondering what component/add-ons we would need now to be the same as what we have? and, Last, (3) Would all the info currently on our site get transferred over automatically upon updating the component? Thanks much for your help, DJ

PHP Version : 5.3.27
MySQL Version : 5.1.56-log
Joomla : 2.5.16
component_com_jevents : 3.1.14
module_mod_jevents_cal : 3.1.14
module_mod_jevents_custom : 3.1.14
module_mod_jevents_filter : 3.1.14
module_mod_jevents_latest : 3.1.14
module_mod_jevents_legend : 3.1.14
module_mod_jevents_switchview : 3.1.14
layout_ruthin : 2.1.2
plugin_finder_jevents : 3.1.14 (not enabled)
plugin_search_eventsearch : 3.1.14