Bron is known as THE light to use for splash shots, it's flash duration is 1/6000 sec ( so they claim ).
What is your experience, what lights do you use ?
I don't do this type of photography myself, but I know Frank Doorhof
does jump photography, and he uses Elinchrom Rangers (Quadra and RX) with A heads. Using 2 of those heads will apparently get you in the 1/5000+ sec. range, according to Frank.
Jumps and moving liquids are both subject to the same gravitational pull, so the only difference is that with liquids you use more magnification, which makes motion even more critical. But the flash duration will be what determines the amount of motion, so it seems that the Rangers are in the same, well, range...
For really high speed flash, you may still need smaller flash heads, like in the Speedlites, but when positioned close to the subject their size does increase proportionally, and you can add a diffuser for a softer effect with less light fall-off over distance.