you can find plugins here:
http://www.msgplus.net/pluginsdb/down/?
so far they all seem compatible with the new msn 7
you can find bug reports and othe things on here, using search - and probably just by putting in the plugin name.
Edit: if you have very old plugins, i'd suggest personally removing them before you upgrade to msn 7.
they should not be a harm, and theoretically they won't cause any problems, but seeing as some things were not compatible with msn 7 beta... and you have not tried it before (with those plugins) i would uninstall the plugins first and add the one's from the link i gave you above.
also, another alternative to see which work.. is upgrading to msn 7, keeping the plugins and getting rid off the ones that cause problems, though if you have many installed.. it may be a problem to detect which one is the cause for errors etc.
/ 
gif 
