This is an international arms trade database. You can use the generator at the following link to find out about arms aquired or supplied by any country.
http://armstrade.sipri.org/arms_trad...e_register.php
It generates a word file which can be saved/printed as you see fit. It covers purchases of major weapons, starting from atgm/manpads at the lower end.
It isn't 100% of course but it seems pretty accurate when checked against others available sources. Short of deep archival searches and the likes it as good as it gets.
Of course it does not tell you what the country has done with those items or who long they stayed in service but it is a start.