slave strobe helpful?

I recently retired my Nikonos III shooting mostly 15mm shots and macro. Have a Cannon Rebel EOS and don't really want to get a huge housing due to all the travel baggage limitations. Bought a little point and shoot Casio but miss the needed strobe power. I thought perhaps a slave strobe on an arm or even hand held would be of benefit. I have come across one or two in the $200-+ range which is fine dollar wise. Anyone out there that can help guide me? I realize the drop in quality but have had enough years working on it with film. Now just want to dive with a simple camera set up but still have the thrill of finding that unusual shot.