Any strain is a good strain for hydroponic cultivation :). Umm if your in a very humid area maybe something a bit more mold resistant like Durban poison would be a good choice. Or if your just looking for big grow.. Gorilla Glue And Gorilla Glue crosses are known for being big produces. As well as the good old fashion Big Bud. Maybe lean more towards indica strains if your height limited as pure sativas tend to stretch a lot more. The beauty of hydro is it's getting everything it needs constantly (when done properly) in conjunction with a good light. Grow Autos if you like the idea of not mucking with light schedules.. Um really it's more about what you wanna grow then anything :).