The most generic suggestion would be for you to check the App store to see if you can find anything that would meet your needs. You can also try doing an internet search to see if you can find anything that would work.
The Iphone unlike android does not have "live" wallpapers.
There are tons of different wallpaper applications in the app store but apple does not support "live" wallpapers.
Why you may ask? Well Live Wallpapers EAT battery! The churning of the animation consumes CPU cycles and thus increases the demand of the phone's battery. So, IMO your better off without them... well assuming optimum battery life is your number one priority.
I know... because when I had my Android phone, I too thought those widgets were cool (along with live wallpapers), but the more fluff you add, the shorter the battery life and for me... I'm way too lazy to constantly remember to plug my phone in. My iPhone 4 under normal use can give me an easy 2-3 days on a charge which rocks and in comparison my Android phone struggled to make it from morning to night.
That's it for me. Battery life. And if Android ever tops Apple in this regard... Significantly, then I'll ... think about .... maybe going back. But.. right now Apple rules.