It sounds like you have the right idea in mind. While there is a chance that the stock price could drop if the acquisition falls through, or rise if a competing offer comes in, both are likely remote possibilities. If it were me, I'd just go with whatever worked the best in regard to taxes and not worry about the rest. I can think of two questions that are worth figuring out . . .
The first (and the one you already mentioned) is whether or not you want to sell in this tax year or next.
The second is around long term versus short term capital gains. If you've held any of the stock less than 12 months, you might see if holding until the acquisition gets you over the line.
Otherwise congratulations on the jump in price! Now you just have to be on the lookout for post-acquisition job cuts . . .
