I cant speak towards adapting what you have, but I would think a simple tap into the brake fluid reservoir would allow the solenoid to work fine. I have the electric solenoid on my trailer and it works fantastically. I have never had a problem with the brakes when backing up.
Assuming you have a ufp tounge, it appears it will not work. Pacific Trailers website (http://www.pacifictrailers.com/UFP-R...p-Valve-34500/
) says it only works with UFP Disc Brake Master Cylinder #34762. I dont know what lockout piece you have but the 2 options are this http://www.pacifictrailers.com/UFP-A...-Lockout-Cap-/
and this http://www.pacifictrailers.com/UFP-A...uator-backing/
(get this one)