best all in one front disc brake kit for a 65 Dart

With Scarebird, you will need to drill new holes in the rotors for your 5 x 4" bolt pattern, or buy the rotors from them already drilled. Most all the choices can be bought as complete kits, it is just a question of price: ~$800 for Wilwood, ~$600 for the 1973+ front disk setup, ~$200 for Scarebird. Replacement parts will be easier and cheaper w/ Scarebird.

You can get the 73+ Mopar disk kit from Dr diff with the small ball joint adaptors to keep the stock UCA's for $480. Includes everything- spindles, caliper brackets, calipers, rotors, bearings, hoses, dust shields and hardware. But it does convert you to BBP. The replacement parts are all stock 73+ A-body though, so, I don't see how that's difficult. Maybe more expensive than the metric stuff the scarebird kit uses though.

The scarebird kit is $105 for just the adaptors, the entire kit is $480 and I don't see bearings and a few other things you'll need in there. Not gonna get that conversion done for $200.