As a starter, you will need to find a rack that is the right length. Than means not only correct overall length, but the correct length center section so you have the correct length tie-rods. This is very impertant to aviod problems with bump steer. Then you need to construct strong mounting points for the rack. After mounting, you will need to determine how to connect the steering wheel to the rack thru shafts and joints.
If it was me, I think I would try to atleast find out what steering rack they use for their kit. May save you some money and alot of time.