installing an ARC system

It is not clear to me what you mean. Do you mean ARC=Anthem Room Correction or Automatic Room Correction or Audio Research Corporation? There are several other meanings for that abbreviation.

If you mean the first of these, it is available only in Anthem prepros or in Paradigm subwoofers. If you mean the second (or third) of these, you can purchase such devices (or software) and use them with almost any system if it has suitable connections.

I don't have a bug for anything except clear meaning.

The only decent all-analog EQ (and not automatic) is the Rives Audio Parcel. All others are digital with analog or digital in/out.

Using a pro is one route but the downside is that you have to hire him every time you make a system change that affects acoustical conditions. In addition, he is on the clock and the avid user can (and, probably, will) apply more continuous effort in optimizing the performance. Admittedly, that will demand learning, attention and effort but, imho, the results will, ultimately, be more satisfying.

There is, also, the issue of choosing a "pro." Not all who profess to be, are.