The most important part of a ceiling fan is its motor. High-end brands usually have the most energy-efficient, well-designed motors, with die cast motor housings. Don't buy a multi-speed fan with only one capacitor inside its motor. A quality fan able to handle three speeds should have at least three capacitors.
Because it's much more complicated to install a ceiling fan than a ceiling light fixture, you might want to consider having your ceiling fan put in by a licensed electrician. Ceiling fans need additional support from above and need to be anchored solidly to a stud (fan rotation can work metal screws loose.)
To remove the popcorn ceiling, start by protecting all the surfaces including floors and walls that you do not want to get damaged or wet. Since water is used in the process be sure to turn off the electricity at the breaker. Use a garden sprayer or spray bottle if you don't mind refilling often and saturate the ceiling. Use a plastic scraper to remove the popcorn material. As a side note if your ceiling was installed in the early seventies it may contain asbestos. Send a small sample to a certified lab prior to removing. While removing the popcorn, chances are some the joint compound was also removed. To insure a flat ceiling refill the joints and any screw/nail holes with fresh joint compound. Let dry, sand and repeat, to insure a flat surface a skim coat may need to be applied. Prime the ceiling with primer recommend for wallboard and a blank slate is created.