MMDuino,
I'd say there are a couple of ways for you to proceed.
1. Get one of the three power supplies you originally listed, if at least one of them meets your desired specifications. Any of them will likely be more than enough.
2. Review the datasheets of the components you'll be using and choose the supply that meets or exceeds the power requirements of those components and satisfies your desired specifications.
To refine the choices beyond this would require diving much deeper into the the many characteristics of power supplies and their associated trade-offs, which could keep you undecided for a while. It's better to get going on your projects and gain experience that will inform your future equipment choices.
For example, one of my precision power supplies provides 20V and 1A with an almost-nonexistent ripple voltage of 0.1mV peak-to-peak (vs. 2mVpp and 0.35mVrms on the DP832A) and voltage selection resolution of less than 0.05mV (vs. 1mv on the DP832A). And it has no fan!
However, current selection resolution is only 10mA, the display resolution is only 250mV and 10mA, and it has only one output.
So, why did I choose it? Well, I rarely operate a power supply in constant current mode, so precision current control is not important to me. My DMM can display voltage down to 0.0001mV, so display resolution on the power supply is not important beyond being able to see that it is still operating near the desired settings. I have a non-precision triple-output supply for general purpose use, so this one is for precision voltage purposes. Schematics and parts are readily available, so it's easy to repair if something goes wrong. It has an amazingly cool user interface, so I get some visual enjoyment from its aesthetics, even when it's not on. And it cost me less than $100, so I can devote funds to more important or more variety of tools and equipment.