Need opinion on this disk brake conversion

Before I make the purchase, I wanted to know what you guys thought of this kit I found online? I was looking at getting it with the tubular control arms for a 72 dart. thanks for your help
http://www.classicperform.com/NewProducts/MoparBrakeKits/Mopar_Brake_Kits.htm

So you have B body or E body disc brake spindles already.
You are changing over to big bolt wheels instead of small bolt wheels?
When that upper tubular needs a ball joint where are you going to get it?
If one of them gets damaged where you going to get a single one?

If you are going big bolt you can use a 73 to 76 upper control arm and spindle set up off sever other year and types of Mopars.