Mike, could not have said it any better, a PM can work and is designed to be way more effective than a single individual, just the systems and staffing alone will trump, you are so right your time is worth way more and no way you can be as diligent and efficient.

It involves engineering the sprinkler system to a specific design which involves CAD time etc.

I think this is mainly for interior design not structural issues.  

I've been a photographer for the past 12 years and do real estate photography and also have a background in design so I'm more than willing to help anyone in those areas if I can. 

Septic tanks are designed to last 50+ years depending how they are cared for (no grease and such) and without tree roots growing into the leeching field.

@William Allen  nice job... always great when the plan works as you design it.

How long in business, are they both administrator and custodian, how many alternative assets under custody, are alternative assets their sole focus, are they BBB rated AND accredited, have they ever been sanctioned by any regulatory body are all very important things to know. 

Does anyone have recommendations for a good architect or designer to help with the plans?

I have an extensive background in mortgage banking and interior design.

I made the mistake of overusing it for years and hurt my body, be careful if you can.