From what I've read about Lewis's spiritual life, he did grow more high church as he got older--attending Anglican confession, etc.--and he was friendly to a lot of Catholic teachings. Some Catholics argue that Lewis would have converted to Catholicism had he lived longer. But to my knowledge he never saw the point in praying to saints, and even later in life, when he wrote Letters to Malcolm, he hadn't changed his mind. The two big doctrinal issues that, he said, kept him from considering Catholicism were its teachings on the Virgin Mary and papal infallibility. He's called Anglo-Catholic sometimes, but he was less Anglo-Catholic than the Anglo-Catholic church nearest me, which definitely believes in prayer to saints.
I enjoyed Letters to Malcolm, although I think I find written prayers more helpful than Lewis did. He started out, I believe, seeing the highest form of prayer as a prayer without words. Eventually he realized that prayer without words is pretty hard to pull off, but I think he always admired it as an ideal.