First thing I would do is verify fuel pressure. The "random misfires" indicate a systemic problem, rather than anything isolated to just those cylinders.
For a 2000, you should have 49 psi, plus or minus 5 psi. Pressure must be tested with a gauge; no shortcuts. Many parts stores will rent you this gauge inexpensively.
How is your idle? Another suspect for the P0300 are vacuum leaks.
Without data, all you have is an OPINION!
Past Jeeps: '49 ******, '81 Scrambler, '88 Comanche
Current Jeep: 1999 XJ Sport, bone stock, daily driver.
I work on Jeeps!!