Ya know when I looked at their Street Grip front springs for a Monte this is what they show. Not coilovers but a really stout front spring rate and a single adj shock https://www.ridetech.com/product/1978-1988-g-body-streetgrip-dual-rate-front-coil-springs-pair/
I am surprised how high the rate is on that front spring, primary 810, secondary 1090. Some would find that a very stiff, busy, harsh for a street car. The compressed length for that spring would be important to effect the ride height. They suggest a 25 3/4" front height with a 2" drop spindle could be obtained. I do know that at 25 3/4" ride height you would need a very stiff spring to keep a fat front tire from rubbing the inner wells.
The Ridetech Street Grip rear coil spring is here, says 2" drop, 26 3/4" ride height, and is also very stiff at 150 -250. https://www.ridetech.com/product/1978-1988-g-body-streetgrip-dual-rate-rear-coil-springs-pair/
And although the picture shows only a pigtail at one end that Ridetech spring is a double pigtails and would just drop right in to the rear. But because it is a short spring at a high rate you would need to be leery of the spring loosing all tension at full droop and possible failing out. A rear droop travel limiter, a cable should be installed with that spring.
If interested I have a like new set of those rear springs which I've never ran in the car but bought to do spring rate testing on.
In the end to achieve the rear coil spring rate and ride height desired a BMR 3rd Gen F-body progressive spring was cut down and used.
I believe there is also a UMI and Global West rear spring laying on the shelf with the Ridetech.
Choices need to be made when choosing ride height, spring rate and ride quality. Because handling only compromises a very small amount of the driving time on most "toy" cars, call them what you like, you need to be subjective about the goals. Really low ride height like a 25 3/4" is much better for the autox and maybe south FL, but in most place will be to low. We need to remember low also is everything under the car, not cool to have skid plates on a Monte.
And to compensate to prevent bottoming a much higher compression rate spring slows the reduction of ground clearance. It's still the same distance/travel to max out available compression distance just requires more weight transfer. A stiffer spring CAN reduce suspension bottoming, but.
Ride quality, as with beauty, is only relative to the driver, and also in my car, my wife. She hates it, I have learned to tolerate what I have put together and most just say it might be one of the tightest car they have ridden in. I'm a 700 lb non progressive spring.
Once you pick spring rates, ride height then you do dampeners, shocks. This is also then when the game changes. Now budget and the need to control travel get into how much is enough. From an over the counter replacement shock, then Bilstein, Koni, single adjustable, double , triple and the cash register doesn't stop ringing longer.
Now the next choice, coilovers,which can be set up for ride height, most times easily, the spring rate can be varied, the shock quality is good at the least and dollars dictates the limits. Would say a good coilover four corner swap would be twice the price of a good coil spring and shock swap.
For most enthusiasts the end usually doesn't justify the means, meaning we usually spend more, expect more, and didn't need what we thought we needed. But it's the nature of the car sickness.
Once you have a good idea of the necessary end result, and the budget, we will be happy to spend your money. That's what are friends for.