Waiting for perfect information is how opportunities time out.

Information keeps arriving, and the point at which it is complete never comes. Meanwhile the thing you are researching has its own schedule, held by other people who are not waiting for you to feel settled. Most opportunities do not get refused; they simply expire while being considered.

Decide what the last piece of information you genuinely need is, and set a date to choose with or without it. If the date arrives and it has not, go with what you have.