While arrow speed is one component to penetration, it is only one part, and not that huge a part. There are lots of discussions you could use the search function for. The Ashby articles are also a great source of information on arrow penetration. The light arrow, high fps is a marketing piece for the compound industry to use in bow sales. Any modern trad bow from a good bowyer, a well tuned arrow from 9 to 15 gpp and a sharp broadhead will do what you need, if you have put in the practice to be consistant. The key is to find a bow you like, fits you, shoots well for you, and has a manageable draw weight. Then just enjoy the journey and the joy of shooting a stick and string and watching your arrow hit where you are looking!