On-X has a grafted valve, but I know nothing about its suitability for your surgery. I can tell you I went with the St. Jude's based on my surgeon's recommendation and my personal review of all the available On-X literature.
As to "preparing for the worst", I think I went about it the same way you did. I expected to come back and did not do much if anything in terms of settling my affairs. Once you get started on that, where do you stop? The risk from AVR and ascending aorta repair is very low. However, I did not appreciate at the time that the risk from the surgery I had is several times higher. Still quite low, but I'm glad I didn't know the real numbers. I was rather calm prior to surgery, rather resigned that this had to be done. That said, it was VERY surreal, primarily because I had no noticeable symptoms. It felt like perhaps I was being "punked" and Kucher might jump out just before the surgeon started to cut on me. No such luck. Over all it went very well, especially since I never had any pain. My biggest problem, a result of thinking I knew more about at least some things than my doctors and nurses, was relaxing and not focusing on all the new and ultimately minor sensations and issues. I didn't sleep for days post-op and finally got a few doses of lorazepam and got some well-needed sleep.