Originally Posted by jasongilliland
My question is this;
What is a good surround that can be cut for a window that does not cost a huge amount?...
...but I know that a good surround should make it completely water proof. Any help would be greatly appreciated!!
You pretty much destroy the "completely water proof" aspect when you cut a hole in it for the window. Windows are a bad idea in a shower because they are a notorious weak point for water penetration which leads to rot, mold and a host of other nasties. I would give serious consideration to either losing the window or replacing it with one high enough not to get hit directly by water.
As far as layout is concerned, can you post a current layout, as well as where you are considering expanding? Location of the door and current fixtures would help others offer suggestions.