@JimHowell1970

    "don't skimp on case or power, especially if you find modules to be expensive - the case protects them and the power gives them life!"

This makes a lot of sense, especially when full cases can exceed several thousands of dollars. Thank you for your input.

    "the psu looks to be a standard meanwell power supply - great if you are only using low powered modules - but not so good if you want to use something high powered - the fact that the builder states the number of power headers, but no the available power may or may not be a cause for concern - I would at least ask before buying"

I admit this is where my lack of knowledge comes into play. I had no idea this was something to keep an eye out for - I just assumed "powered case" would be enough to power any combination of modules that fit into the case. Thank you for the advice.

    "personally I prefer the mantis over either of these cases - but that may just be me, partly because the mantis power supply is clean enough for video (less ripple up to much higher frequencies) whereas by all reports the intellijel supplies are not so quiet"

I would probably already own a Mantis case if I wasn't also so picky about aesthetics (even though it's a little bit larger than I'd like)! I like making videos with my synth gear and having a good looking case that appeals to me is part of the whole package. You mention the possibility of video "noise" and some power supplies not being clean enough. Is there a proximity effect to this? i.e. Would I need to be careful about how close my camera gets to my gear if my case happens to have an "unclean" power supply?

I've done a lot more searching around the net and have come across another small but seemingly reputable eurorack case builder from France that mentions a LOT more detail about the cases they make: Modulaire Maritime.
https://www.etsy.com/ca/listing/663523749/modulaire-maritime-accra-6u-eurorack

Can you speak to the power supply used in this build? The size is exactly what I'm looking for (I have decided on 6U, 84-88 hp would be more than enough for a long term build) and I really like the aesthetics of it.

    "not many people can afford to go out and fill a case with modules on day 1 - and it's not often recommended either - whilst most modules are relatively simple to understand, lots of them all at once is not - and those that do need a bit more time generally fail to get it when purchased in huge batches - so starting with a few modules and learning them in depth before expanding is a great idea"

Again, another great point made and something I instinctively abide by. I've been working with two Moog semi-modulars for just over a year now and still have more to explore with them. Although it's time to augment that setup with this new modular journey :)

Thank you for all of your recommendations around how to output, modulation, attenuation, etc. Definitely gives me a solid starting point and feeling a little more comfortable with my starting module choices and some ideas on how to support them with more utility.

@defragmenteur
Thank you for the info about the MIDI modules.

@Lugia
Thanks, I appreciate the advice. I've decided to go with a larger case (6U, and 84-88hp) as it will allow more room for expansion and won't be too overwhelming in my studio.