Land Rover Repair: 2000 LR Disco II Issues, plug wires, catalytic converter

Question
I bought this vehicle with 102k+ miles on it and literally as soon as I drove it off the lot the Service Engine light came on.  Got it checked and it read a cylinder 4 misfire.  Per mechanic, all plugs were good.  He changed the ignition coil, but that didn't work.  LR Dealer said the major issues were: aftermarket parts, an exhaust leak, and incorrect coolant; requiring 60k service to replace parts, new catalytic converter for the exhaust issue, complete system flush, and new plug wires.  Does this sound right to you?  As far as driving the vehicle it hesitates, slightly when idling, engine ticking, when it's hot [outside] the startup is rough and the service engine light actually blinks a few times until I rev it and hold it at about 2.5k RPM.  The service engine light will actually go off for a day or two, but come back on when the "rough start" occurs.

Answer
First, I would never change the coil without also changing the wires and plugs.  I'd look closer at them.

It sounds like the dealer has identified more problems than the first shop, but the "complete system flush" and "60k service" is just selling you maintenance.  Which you may need, but at this moment you've got a running problem to fix.