I don't work on LG appliance's, However I do work on dryers.
Anyway, I wouldn't stock up on to many parts before the machine breaks. You never know what is gonna go bad, and you could have a pile of parts that you'll never use.
Most common parts on dryers that fail are, Gas coils, Safety thermostat, Hi limit Thermostat, Belt, Drum rollers, Control Boards, Thermistors.
With that said, Who knows what will fail.
The igniter can be changed from the front of the machine only, the top needs to be pulled, then the control, then the front to access all of the components of the machine.