if they are already contacts in Solve, you can relate them to the project
if not, just make a formatted note and list them
or create a google doc spreadsheet and list them there and easily sort or manipulate the sheet as you need
or insert the link to their LinkedIn profile as a Web Link

just my thoughts

Using the “related to” is a good option. That way you can specify that they are potential candidates in the “how do they relate” field.