I'm a long time B2B marketer and grew up (early in my career) in
distribution. If you run this search: *distributor magazine* in Google, you
will find any number of distributor publications. You should be able to get
circulation reports from the publications. Lists should be pretty granular,
meaning geography, job title, size of company. Suppose a publication has a
circulation of 20,000. It's a snap for them to tell you how many of their
list members fit your criteria.
So let's say, since smaller businesses would likely make up most of their
list, and by the time you exclude certain irrelevant titles, you learn that
they have 4,000 names of interest to you. With a little begging, pleading
and requesting, you should be able to obtain an every nth name test list of
200-500 names at no charge on the premise that if you test with this list
and are successful, you'll buy the full list. You can also often work the
*rep* to arrange for a new product press release (not the editor). They
will often do this for a new company.
You can add a country name for out of the US or conduct the search on
for the UK, ditto for Australia, etc.
Hope that helps.
Let me know if I may be of further service.