Hi Joakim - my understanding is that the SB104/5 don't have the capacity to deliver the quick succession of pre-flashes required under the i-TTL protocol. So it is not so much that a converter cannot provide an appropriate signal for them, but that the strobes can't 'implement' the provided as required - if that makes sense. So no converter will give you i-TTL with those strobes as I understand it. I actually had the SB105s when I first switched to digital, but have since moved to DS125s which I can recommend.
That is not to say that you can't continue to use the SB 105/4 strobes in manual flash mode. Many people here actually prefer manual mode, particularly for wide angle photos see TTL Anonymous for more discussion. In fact, I still use manual for wide angle shots.
Alternatively, you could look at one of the Ikelite converters and their strobes...which will work with your housing.
http://ikelite.com/web_two/ittl_adapter.html
Perhaps speak to Ryan at Reef Photo Video - see link in the ads on the RHS of the screen - about suggested options?