You can buy everything seen in the "upgrade/edit appearance" menu very easily.
First earn over 100.000 pounds in career mode then enter the "upgrade/edit appearance" menu. Now buy everything you can afford DO NOT CLICK ON DONE or you will lose your money. when all your money is spent press the B button to go back to the main menu and save your game. Now when you return to the "upgrade/edit appearance" menu you will have all you bought and still have your earnings. Repeat this to buy everything.
Win every match easily
When playing in career mode if you win a frame save your game if you lose then dont. Buy saving only when you win a frame you can repeat the match till you win thus winning every tournament easily.