I have a YS-25 and wouldnt recommend it. It will attach fine to almost any housing in that it uses a velcroed fibre optic connection but it uses a metering system thats eventually really annoying as you get better - it has its own on board sensor that decides the flash level based on what f-stop you set it to on the strobe.
Because it uses its own light sensor, in practise it can be quite unreliable in its light levels, especially if you dont want to point the strobe directly at what you're taking a picture of, which is generally the case if you're trying to minimise backscatter.
Given the price of an Ikelite Ds-50 plus manual controller is almost identical to a Ys-25auto + fibre optic cable at the site I checked, Id say its a much better option, and its output is much better as well. The other option would be an Inon, they're a little bit more but offer the option of both TTL and manual.
Otara