An electric driver is used to assemble flat pack furniture, and it can be used together with any bit. Not all electric screwdrivers can serve to meet your goals as some claim features they do not have. To purchase the best electric screwdriver, you need to consider three things:
Voltage
Rotation speed
Amp/hour rating
Besides, each of these tools serves better when used on specific functions. For regular use like assembling pieces of furniture weekly, settle for a high voltage screwdriver with a good Ah rating. Go for that with 3.6 to 4 volts and has a tightening torque of 5 Nm. For occasional use like assembling pieces of furniture yearly, settle for one with at least 1 Ah and 3 Nm. Besides, buy a lightweight one for comfort while using.
Use the above tips to buy the best tool that will serve you better and meet your goals.