Although I did not opt to get an ileostomy when my J pouch needed to be removed, perhaps relating my experience would be helpful. I had my J pouch for 30 years and had 3 operations. Undoubtedly, those surgeries were a factor for creating numerous dense adhesions that made J pouch removal more difficult for my surgeon. It is not an easy operation and some people find that it can take quite a while for their bottom to heal. I had no problems with this and no infections developed. I would not recommend leaving the J pouch in because future problems could develop with it. Some people have had their anal sphincter retained with the thought that they may want to try another J pouch in the future.
Although many people have had good results with ileostomies and there have been improvements in the appliances, I decided to get a BCIR (very similar to a Kock pouch) based on the quality of life it offers. This procedure does not require having an exterior bag and avoids many of the issues that those with conventional ileostomies can have. There is a high success rate with these procedures and they have a high degree of patient satisfaction. There is considerable information about both of these procedures on the internet. It does not surprise me that your two surgeons recommended an ileostomy and likely did not mention alternative options. Many doctors are not aware that these procedures exist or may have outdated and inaccurate information about them. If you have interest in considering these options, I would suggest that you contact a surgeon who does them to see if you would be a candidate to get one. Please feel free to send me a PM if you have any questions.