Has anyone had a tub to shower conversion similar to the one at above website?
You may want to rename the thread to something that refers to cutting the side of the tub. Right now, your thread may be interpreted to removing the tub and installing a new shower.
There are a lot of companies selling inserts for this type of application. It looks pretty neat and easy to do.
You may want to also post on the Terry Love Plumbing forum - shower and bathtub section.
Here is a link that might be useful: Terry Love forum