If the acquisition offer is enough money to matter, then take it. You wont be at the acquirer for the rest of your life, you will get a lump of money plus a steady salary while you are there, and you will learn a lot about other potential problems to solve in your space. In 2-3 years, go after your other idea with a financial cushion in the bank, a successful acquisition under your belt, and some industry tenure to make your next move better.