I'm adding a pond palace to my pond. It's a cave that let's my koi hide from the herons and has super fine bubbles that the fish love swimming though. I got mine from Richdeer3 Pond Supplies.

Here is a link that might be useful: Richdeer3

Nice pond!!
I am in the process of improving my small pond (around 1000+gal ). Because mine pond is in front of my porch (feng shui), I had to put a fence around it to prevent kids from falling in. This fence is ugly. so I am looking into building a stone wall around the pond and raises the pond about a foot above ground to give more capacity for the pond.
it's going to be lots of work but FUN!
also check out this site for your project ideas http://www.aquaart.com/help.html

I hate my fence, too. I had great luck covering it one year with annual sweet potato vines, lots of colors and leaf sizes. It even grew in the water and the fish didn't seem to bother it. I now have morning glories and sweet peas on the chain link fence. Good luck hiding the eyesore!