Wow I also consider to build a e-lsd, never thought that someone have the same idea with me 
I just made a search and found out some pretty strong linear actuator but was too expensive(250E).
So i tried a windscreen wiper motor from a bmw and was ultra strong, I used this to operate the clutch of an R6 yamaha engine for an FSAE car. It was able to pull about 20kG in a 4cm lever with a very good mosfet H-bridge @12V(PC PSU). So a total pull of about <8cm which is too much for e-brake cable, potential a smaller arm can used to gain some force. In my project i build a small drum out of a pipe in order to have steady force an unlimited travel cause the 20kg was not enough so with 2cm drum diameter i manage to pull the clutch in less than 1 second and with a single turn a travel of Pi*D = 6,...cm which was enough
If you plan to use two motor you can help the window motor with a spring not torsional.
Do you know how to pick the signal of the VR sensor without affect the ABS reading i dont want ABS to fail in any case. Maybe a high impedance input did not affected but I am not an electronic guy.
Also there are some IC that coverts the frequency to voltage but it needs zero crossing, so they are suitable for VR sensor in the other hand doesnt work with hall effect.