Contingency plans for other sources of income.
Seems like more often than not, a seller staying with the company buying them out never lasts that long.
I’d be very skeptical of the idea that you’ll be secured in your job for that long. Make sure you’re planning the worst case scenario, not the best.
I also think that this decision needs to be more than strict finances. Do you enjoy what you do? Will you enjoy working for your same company with no control or voice in decisions?