I've used yonguo flashes (http://www.hkyongnuo.com/e-detail.php?ID=236) and triggers (http://www.hkyongnuo.com/e-detail.php?ID=255) successfully on an RZ67. Those models have both been superseded now but if you're on a budget, they go OK in a small space.

I don't have enough room for dedicated studio lights but given the opportunity, I'd get some. The yongnuo stuff is very portable too though. Combined with a nice modifier and a flash meter, you're sorted.