why do you think the wires are overheating? are they physically hot to the touch? if you have isolated it to the spark plugs/wires for sure (which to my limited knowledge doesn't sound like it would be this problem) have you made sure the plugs are properly gapped?
what do you mean by engine sounds bad? rev pattern off? stutters going up hill? There are a lot of people here who will help, just need a bit more to go on.
"All that is necessary for evil to triumph is for good men to do nothing" - Edmund Burke