A biopsy is needed to send a sample to the pathologist to see if in fact it is cancer. As in most tumors, a second surgery is often done (especially in bladder cancer-called a TURB) to be sure of the grade and margins are taken to be sure it hasn't progressed further than the first biopsy showed.
Northwestern indeed has an excellent reputation although I know nothing about Dr. Koslowski. It does sound HudsonGirl has given you a good ref.
On having kids. I am on shaky ground as I haven't had my bladder out but, that is something to discuss with your URO. I don't see why you couldn't have kids however. Usually the prostate goes out with the bladder but, there is "nerve sparing surgery" to keep a males parts in working order while some take time to function/erection. Also, as the sperm is made in the testicles I see no reason why you couldn't have kids-even of you needed to freeze some. There are several guys that can give you more info as they have had a cystectomy done and hopefully they will chime in.
Keep asking questions as someone will have gone through in a similar fashion. Lot's of success stories here.
Also, if the tests do concur as bladder cancer, if it hasn't invaded the muscle part there are other treatments like BCG (see this site and others for info). It is no fun waiting but, take each day and step one at a time.