The process for building your car is not very dissimilar from a complete frame off restoration. The basic steps are
01 Purchase the appropriate vehicle
02 Determine final package with the customer
03 Remove the body and send it to the paint shop 
04 Prep the frame 
05 Create the rolling chassis with all of the upgrades in parallel with the painting process
06 In parallel complete the painting process 
07 Mate the body and frame
08 Install interior, AC, sound, etc. 
09 Drive 500 miles 
10 Detail & Deliver to customer