Actually, you need 333FSB to reach 3GHz on a E4300.Welcome to TG Forumz 8)
Too easy, to reach 3GHz you'll have to raise your FSB to 300MHz. That will put your RAM at DDR2-600 speeds. So any RAM rated for DDR2-667 speeds will work fine. You can find DDR2-667 for as low as $120 for 2GB on newegg 8O