I'll always edit wedding picture using Photoshop and video for slide picture.
Is it suitable, perfect, smooth, fast if i upgrade MacBook Pro 13-inch 2.53GHz like below:
Just get the 2.26ghz model and upgrade it yourself.
Here's a 500GB HDD for $85 and 8GB of RAM for $400, though I am pretty sure 4GB of RAM will be more then enough and that would only cost you about $100.