I have never seen a lift for an Outback but I'm sure for enough money someone could make one. The Outback is not the same type of 4WD as the early model Sportage. The Kia has a part time transfer case with a low range gear. Your Subaru is full time with no low range. The Subaru is a great all weather car built to look like a suv and handle like a car. It is not designed off road like you have allready descovered with speed-bumps. If you are not into 4wheeling you have a great reliable vehicle. If you just want to clear speed bumps try to find out the tallest tire you can fit, it might use a little more gas but not much.
Hope I helped a little, Dennis