I personally dont think that any designer can setup a gambling sites with his only designing skills. Setting up a nice gambling site need other stuff also which is more important then a design.
OP first must need to care about security of the casino or any gambling site because in last few years we saw many horror stories where hackers tried to hack the site and stole their bitcoins in seconds . So OP must need to care about security first then it comes to the design section.
Btw there are many nice premade software availables in the market but you need to pay premium prices for those .