I don't know if you have fixed your problem yet or not, but this is what *I* would do to my car:
If my spark plugs and wires had more than 30K miles on them, I'd change them. Then I'd run SEA FOAM or Berryman's Chemtool through it to clean out any carbon, then change the oil and filter and check/replace the air filter and maybe even the fuel filter if it had been a while.
The oil on the spark plugs you mentioned could just be the valve cover gasket has a leak and shouldn't be too difficult to fix if you can do minor stuff yourself.
If that didn't fix the problem, I'd take it to a good mechanic.
:::insert standard "do at your own risk" disclaimer here:::