Yes, you can fit your stock tires on a 18x9.
However, those wheels will not fit your JK. Your new Jeep has a bolt pattern of 5x5. The wheels you liked to have a pattern of 5x4.5. Those wheels also have an offset of +20, which would put backspacing at 5.8". If you never intend to run a tire much wider than stock, then that would work. However, if you do intend to run a decent size tire one of these days, then you want to get a wheel with an offset of 0 or less which would put backspacing in the 4.5" range, depending on the width of the wheel.