The price seems reasonable enough. But of course you said you also needed 8 Lug Rotors, those pictured-priced are the 6 Lug model. I didn't search to see what they had available for your other vehicle?
I assume the Calipers are simply just reman stock units, but might be an improvement, and more reliable if your Calipers are up in age.
A better Pad material such as Ceramic should up the effectiveness of braking, and eliminate some fading under heavy duty use, which stock pads are often prone to. I understand there is also less dusting with Ceramic Pads.
I'm no definitive expert on braking systems, but usually, it seems like stock pads, and pads that come on a vehicle from factory, or cheapie quality always wear out quickly. That usually a good aftermarket pad should be an improvement, both for performance, and longevity.
I'd assume a harder material pad with higher operating temp range also probably places slightly more faster wear on a Rotor. That's the compromise, Can't have it all I reckon.
Slotted-Cross Drilled Rotors again should improve brake efficiency. I have often read though that cheaply done cross drilled Rotors can have a tendency to begin thermal cracking at the cross drilled holes.
Wish I could offer more insight-advice on these, and how the company as a whole is.
For sure, any good upgrades to a brake system gives an improvement in safety.
Mark