I pretty much believe in "there are no bolt-on parts". You cannot just slap a set of different carbs (or other parts) on an engine and assume it would work right. In fact it is almost guaranteed to do the opposite. You would need to know how each carb model and application works, what jet and emulsion tube etc. does what, to be able to tune it to your engine's needs in every situation. This means replacing a bunch of parts to find the right combination. You would need to have access to these parts in various different sizes. Plus you would need to be able to verify the results reliably, forget "tune by ear". For most street applications and an experienced tuner, a regular narrow band O2 sensor would suffice. If you can't get it in the ballpark from the start, you need a wideband setup. (more expensive, but more forgiving as it offers a wider range of data values as the name implies).
This in mind... armed with experience and spare parts, you should be able to make any carb work. Or any multiples of them.
The progressive dual weber is a common "replacement" carb, geared towards smooth progression and driveability, as well as economy. When used to replace a single throat carb, it usually offers more power due to the additional second throat flow.
But it is not a performance carburator. These were factory carbs on many older cars. Think "4 cylinder Ford Pinto" and you get the idea. They are less "tuneable".
The DCOE series is a performance carb, which while FULLY streetable and smooth to drive when tuned right, allows for more power potential. It generally is used in applications where you have dedicated, individual intake runners, one carb venturi for each intake valve. You can tune the mixture for each individual cylinder. They have also been used in shared venturi applications, but they aren't optimal for plenum intakes.
The Progressive Weber is designed for setups where there is a shared plenum space immediately under the intake, a "mixing bowl" where all mixture is first dumped, and each cylinder then draws from that general mess of fuel and air. The said plenum needs to be HOT, to keep the mixture alive and prevent fuel from falling out of suspension and creating droplets of raw fuel, which won't burn. This plenum design results in less accurate mixture control for individual cylinders, but works fairly well when everything is well matched. Sadly, by having to heat the mixture, you lose some power potential. From a performance standpoint, you want the ingoing mixture (air) to be as cool as possible.
Since the progressive webers have fewer parts that are replaceable or adjustable, they are basically simpler to tune. AND would work reasonably well in our plenum-type intake configurations.
