If you're set on switching to a typical disc brake kit you'll need to switch to '37-'41 spindles, or '42-48 (will probably need a different kit bracket since the first is round back, the latter are square). The king pin dimensions are compatible with the stock axle, and new pins and bushings would be a smart refurbishment while it's apart. If you get stock Ford pieces that haven't been modified the steering arms will be the same as the stock '36. The aftermarket repops of the '37-41 don't have steering arms so those would need to be acquired also. Make sure you get forged ones if you go repop, not just cast cheapies.