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[The_Almighty_Bacon_Lord]

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[MosherIV]

So, I'm slowly gathering all of the parts needed to make a 0.015-30V 0.100-4A (2 channels) bench power supply!

30V * 4 = 120W
That is a lot of power to dissipate, are you sure you can get rid of that much power without getting the heat sink too hot? 

In any case, here is a project with a single channel PSU which allows you to set the volts and current limit.
http://www.microsyl.com/index.php/2010/03/31/bench-power-supply-0-25v-0-5amp/
The project does show set V acutal V, set A limit and actual A.

The schematic is the easiest that I have found to follow for this kind of PSU.

EDIT : I wish beginners would stop refereeing to the current limit as constant current - that is a totally different type of PSU.

[MosherIV]

P.S: Sorry about mixing up my words of constant current and current limit! I called it constant current because that's what the buck converter can say it does!

Common newbee mistake. Most buck/boost converters can be used in either Constant Voltage OR Constant Current mode.
They CANNOT do both at the same time.

Your description did not make it clear that you are using buck converters.

To use buck converters as CV, you take the output V and feed it back to the controller sense via a voltage divider (eg a potentiometer).

I would suggest looking at the design I posted for how to add current limit.
It works by using a current shunt (accurate low ohm resistor) and comparing the current output against a set limit.
If the current output reaches or tries to go over the set limit, the op-amp starts to try and drive the output voltage down - there by maintaining the current limit.

In order to make this work with the buck regulator, you will have to do a similar ORing arrangement with the set voltage ( the feed back to the controller sense )

Never done this before, so good luck