I would like to by a 182. I am practicing maneuvers for my PPL checkride. What hurdles do I can to cross?
Sure but more skill is needed to fly a heavier, higher-power aircraft than most students use. The aircraft that you fly the most will become the easiest to fly as you get used to it. Students are usually overwhelmed with controlling the aircraft, navigating and communicating. They are often hard on the airplane in bounced landings. Trying to master a more complicated, heavier and higher performance airplane puts even more pressure on the student. A student's ability to learn all of the skills required to be safe and proficient is an individual thing. You might be able to handle it in a 182 or you might find it too much. For a nose wheel aircraft, I think the 182 is ideal since it has the load-carrying capability and power that you need for 4 people with baggage and full fuel. They are not inexpensive, though. I recommend that you rent one first to see if it's your cup of tea.
You certainly CAN do that, but if you're just short of your PPL checkride, it wouldn't be a good idea. Changing horses that close to the other shore of the stream is just asking to extend your training significantly. Better to wait until you finish the PPL ride before you start thinking about buying something different than what you're training in now.
And when you DO get to that opposite shore, AOPA's web site has a section chock full of good information on buying your first airplane.