Thanks everyone. I checked the backscatter thread, but am still confused about which would perform better in this specific circumstance. I am not too concerned about weight on land, but about the ability to manuever through a high flow cave with the strobes. Since many of the Florida caves tend to have dark walls, I'd also like him to have as much coverage/illumination as possible.
I am interested in purchasing a housing and strobes for the Nikon D200 to be used primarily for cave photography in North Florida as a gift for my husband. He wants the Hugyfot housing, but I am confused when it comes to strobes. I am considering the Inon Z-240 or the Sea and Sea YS-250Pro TTL strobes. I like the size of the Inon strobes, but have heard that they may not have enough coverage. The Sea and Sea strobes have better coverage, but are bulkier. Any suggestions including other strobes to consider are much appreciated.