Only the page linked to you will help your
PR. But the problem is that if a page has PR4+, most likely the webmaster will not use this page to link with others. So your choice will be only those higher
PR homepage but lower
pr link page, sooner or later, homepage will pass some
pr to the inner page. Only takes some time.
For long term, you shall try to rank at the top in google instead of Ads. Forget my suggestion if you have a lot money.