Solo-Founders, who or where do you ask for opinion?

I will probably look for people I know and recognize in some way, and will look for them from around me, and even less from strangers due to privacy issues, a trust that is very difficult to build.

Communities like IH, PH and reddit is a good place to ask questions. Or you can use twitter

I am part of many communities and have been working on building my own network to tap into for advice, suggestions etc.

Networking events, online communities, and industry-specific forums are great places to find people who can offer valuable insights.