I'd use a drop down list for this. You can place the name field from the related table next to or even on top of the drop down list so that the name is displayed after you exit the field. (If you put the field on top, use the inspector's behavior tab to deny access to the related field when in browse mode.)
tables for People and Companies, are linked by Company Name
Actually, they are linked by companyID aren't they?
There are also enhanced value selection methods you can use to make long value lists more manageable.
Here's a link to a demo file with examples of 4 different enhanced value selection methods. All require scripting and the two portal based examples require FileMaker 11.
Got a chance to explore this today. very elegant. Thanks!