A combination charity/loan program might be a good idea, especially if you involved parents of students who already had computers. If only 7% of students don't have computers, chances are among the other 93% there are those that have old computers sitting around at home unused. If you encourage them to donate those old computers to the school and redistribute them on a loan basis to students that don't have any, you might achieve 100% coverage. But then you've also got the problem that the 7% may not be able to afford internet access either.
If you do have inequalities like this, you must make sure they don't affect the non-computer students negatively in terms of their grade-earning abilties. It might seem like it should go without saying but I will never forget a project my English teacher had us do back in high school in the late 80s. We were all working together to put together a book of our writings. She graded us simply on how much time we put into the project. However, this meant the two or three students who had Macintosh computers at home and who typed up our documents for inclusion in the book automatically had the ability to get better grades than the rest of us. Because for the rest of us there simply wasn't enough other work to do to make it equitable.