Not really because the official brake package was in flux for your car. Disc brakes were offered as a HD upgrade on Police 9C1 packages and cars that someone wanted to convert into a hot rod stating in 1968 (some say 1967 but I haven't ever seen one).
My mothers 1968 Caprice had front disc brakes and it had 15 inch Rally wheels.
In 1968 the Disc brake package was unique to the B-body platform and used the rear rotor off of a 1967 Corvette with a special wheel bub (hat) that isn't reproduced (if it were you could buy all of your parts off of a Corvette restoration web site). The Corvette brakes used were the four puck fixed bridge Girling brake design popular in European sports cars as there were lots of used WWII fighter and bomber brakes that used these parts still lying around waiting to be salvaged and reused.
In 1969 GM engineers at the request of the bean counters introduced a single piston floating disc brake caliper for use on the Camaro, Chevelle and the Nova. They built a lager diameter piston caliper with a thicker rotor (similar once again to the Corvette front rotor) that didn't require a separate hat to mount the disc as the bearing races fit in the disc rotor. GM engineers made two different size brake systems (based upon car weight), and offered them on the 1969 and 1970 model years as an upgrade to the stock drum brakes. Because these parts were relatively rare initially (not many saw the need for disc brakes), and because they only were made for two years the disc brakes for your car are hard to find. In fact it is easier to find the one year only Corvette four piston disc brake kits than it is for the newer one piston design because Corvette reproduction houses offer everything except the wheel hub.
The low cost aftermarket kits contain brake parts off of a Chevelle or Monte Carlo that the factory engineers thought were too small to provide adequate brake protection. They sell these kits using cheap imported discount corner auto part store parts instead of the better quality parts sold to replace the same make and model used as a host vehicle that you could but from the Chevrolet dealer, or off of NAPA's high quality shelves. (Even NAPA now sells
to compete with the discount auto parts store because American consumers have been trained by WalMart and Dollar General to think that what they buy has value).
There are lot of companies diving to the bottom of the price barrel to feed the needs of the automotive hobbyist. They all sell the same kits as if you research on line there is a formula of stock Chevy parts that they put together to make these kits.
Personally if I am using a vehicle that doesn't have disc brakes offered as a readily available service part I Use Wilwood or Baer brake kits. Even if the car has am 11 inch disc and nine inch drum found on Nova's I will occasionally upgrade to a 12 or 13 inch front disc from Wilwood or Baer with an 11 inch rear drum brake, if I am not converting everything over to C5 disc brakes to autocross the car.
By the way no mater what company you buy your disc brake conversion from it will push your front wheels out a half inch to five eighths of an inch more than the drum does now often causing a wheel and tire change to prevent rubbing.