I used Uunder Gravel Jets too.
When I did my rescape, I put all my rocks on eggcrate with legs. ie all the rocks are raised off the bottom so there is a load of flow going beneath them. Basically, everything falls through the rocks to the sand, then the UGJ blows them into my filter. It's great, I love UGJ systems, they are worth doing for sure.
Your tank looks amazing, apart from the turtles. The jets looks superb, I only went for less in my tank as I wanted them to be more powerful.
This is it with all the front rock stripped away:
Video of jets during a rescape:
http://www.youtube.com/watch?v=F8ltEHFalWQ