I had a "mini-sternotomy" with a tissue valve, and can tell you that the healing time is much faster, and with less discomfort. It is possible to get the minimally invasive procedure for an aortic valve between the ribs, without the sternum being involved. I believe Richie Rich had this procedure done. However, this will involve a different approach to hooking you up to the heart/lung machine, so you also have an incision (small) in your groin for a balloon catheter.
The truth about minimally invasive heart surgery is that it requires additional training for the surgeon and staff, and perhaps an extra level of surgical skill. If you pursue this option, make sure it is through a hospital that does lots of them.
It is funny how different surgeons will give you different answers; it is all skewed by their own training and experience (same way the rest of us form opinions). My gripe is that I've NEVER heard a surgeon say, "Yes, that is an option, but I don't have the training or skill to do it."
Good luck with your search for a surgeon!
--John