Junebug, I am a bit jet-lagged at present, but when I saw your post, I had to chime in. The next few months will be difficult, but rewarding to your family, as you all learn and decide and ponder and come together. My husband died of metastasized bladder cancer in November, and, if I had it to do over, I would not have pushed for the last two chemos. I think his quality of life would have been better.
That's my two cents worth. Let us know more about your dad, and his history, and his treatment plan, and what sort of talks you have had with him and your mom. I think there are people here with lots of experience that could be of help. Don't be afraid to come out of lurk mode and ask questions.
Stephany in Iowa (finally)