The thing that does come into play with the 138S Durst and the possible conversion that has been mentioned is that as the size of the light source relative to the condensors is increased then one loses the benefits of an condensor enlarger. Condensors serve the purpose of collimating the light bundle.
The ideal conversion, I would think, would be to use a point light source or even the high wattage and low voltage halogen conversion that Durst Pro has developed and then passing this light emission through a set of dichroic filters that would be incorporated in the area of the filter drawer. Shouldn't be too difficult to accomplish.
I have three of these particular enlarger and this may be an idea for a conversion of one of them.