having a J-Pouch to replace Ileostomy

A J-pouch isn't a foolish choice, but it also isn't "free." Most people with J-pouches are happy with them, but they can be more challenging to manage than an ostomy, and the road back from the surgery can be difficult. The advantages of a J-pouch are aesthetic (nothing poop-related to see), psychological (normal body image), and functional (no bag to deal with during various activities, or preventing some of those activities). Some folks find an ostomy to be a barrier to sexual intimacy, and others don't seem to be the least bit impeded. So you have to weigh how much you'd prefer to be without the bag against the challenges and risks of the surgery.

In my case I took up martial arts and scuba diving after my J-pouch surgery. An ostomy would have made both of those choices much more complicated (at best), though I had no idea I would start those activities when I chose the surgery.

Good luck!

You should have an anal manometry test first and foremost to test the strength of the sphincters -- after nine years there is a strong possibility that adequate sphincter strength is not there anymore and a j-pouch would be a poor experience for you. I would not proceed without one... in fact, in your shoes I wouldn't even consider whether I want the pouch or not until getting a positive result on the test.