technomate receivers have the best support as do echolink.
as for a cam, dragon cam is good best at the moment is the diablo lite 2.3.
unless your dragon cam is faulty i would stick with it as there are plenty of updates for it on this site.
as for a card most are going for the abracadabra card but this will only work with certain receivers.
you didnt say what receiver you have.
i myself prefer technomate as so easy to update and works fine with both dragon and diablo cams.
am sure the more experienced will give you more info if still needed.
hope this helped you abit.