Every freenet's directors while have to deal with the ethical dilemmas involved. My personal view is that we have an obligation to ask for this money and see that it is used to create a fully informed public. But, we have to avoid being abused by the worst of these offers. An example of abuse by a cause related marketing scheme is this gem. New Yorkers would have had to order half a million meals just to match the ad budget.
Most major firms donate some services.
Law firms are often required to do so. If you can't get equipment donated - try getting it loaned. If local resources are poor try getting a preferential price. Freenets by their nature are not on the cutting edge of computer technology. Your success rate will be highest if you know the product lines and consistently ask for last years models.