https://bitcointalksearch.org/topic/free-script-untitled-dice-run-your-own-bitcoin-dice-site-no-server-needed-1062680
I believe moneypot would be a good starter, but it will be hard to get people using your site. The interface is bland, and unless you have experience with CSS or visual design, i'd highly discourage using moneypot.
If you have a good API knowledge, you can find a dice script online and hook it up with Moneypot's API.
You can make your site look however you want and still use MP. I don't know where the idea comes from that it will look bland. MP is just for pushing the bets -- you can take any script and use it, regardless of how it looks on the front-end.