This is a conversion I'm doing, as well. My trailer currently has twin axle Kodiak discs and a surge controller.
I bought the severe duty Brakerite kit from
https://www.southwestwheel.com/store/p-161-d7brakeritesd.aspx for $799,
and additional $74 for an adapter to my Chevy controller plus $67.15 shipping to my door. It will plug into my existing 7 pin trailer plug, keeping the break-away battery charged.
I'm doing the install along the lines in the manual for an aluminum Shorelander:
http://www.midwestindustries.com/documents/manuals/08TA0016.pdf
I'll bolt the surge slide, as someone else mentioned. Apparently, if I'm careful doing the hydraulic connections, I can even avoid the need to bleed the complete system.
It looks pretty straight forward and shouldn't take more than a 1/2 day. (barring a murphy intervention -

)