Here's what I think based on the very limited information given on your plan:
1. The stand is too tall. It is better to have the kettles lower for more convenient access.
2. The electrical outlet is of little importance one way or the other at this poing.
3. The March pump is OK
4. I don't have any experience with the Shark Bite fittings, but I think there are better ways to go. Brass and copper are OK to use. Stainless is nice, but more costly and not an absolute necessity.
5. Don't worry about the appearance of the stand at this point. You can easily paint it and it's not a big deal.
6. The Bayou Classic SQ-14 is an excellent burner and an excellent choice IMO.
7. The chiller looks good and the larger 1/2" OD tubing was a good choice. It's well worth the extra cost.
So, that's my take on it so far. IMO, stands or "rigs" are not at all necessary, although, for some reason they have sort of become the default configuration. Modular systems are my preference. Plan out your system on paper before you go much further. This will save you time and money in the long run. Often, when putting a system together, you will buy or build something only to upgrade it not long after. I think most of us have been there and probably more than once. Plan the project well, then build to the plan for best results.