Hi Erza5, considering the age of your father, neobladder is definitely the first choice for the urinary diversion, provided you choose the doctor who has done many neobladder surgeries. There is some complication like hypo-retention but it is less than 5% chance. It is a good choice to have the bladder removed even though it is not muscle-invasive because it gives your dad the best chance to live the longest.
The main concern for neobladder is continency. Most neobladder patients learn to be continent during the day, but some may not be able to learn to become continent while sleeping. Still, there are some devices like condom catheter which a neobladder patient can use during the sleep to avoid leakage. As a matter of fact, I know a man who says prefer a condom catheter as he can sleep through the night. Also considering relatively young age of your father, the other main factor is that other diversions such as ileal conduit or Indiana pouch require the use of urostomy bags or single-use intermittent catheters for which the lifetime cost can be substantial if your dad is not fully covered by the insurance.
Best wishes.