I would have said test but he said he didnt have access to a comp tester etc.

The plug sounds like it looks fouled, not really any other way to check for a good spark. Plugs are dirt cheap anyway. Leads? Well if they are new i doubt they are broken, ive fitted 100s of HT lead sets and never incountered a faulty lead from new.

Comp test, do a dry test first. Hold your foot flat to the floor on the acc with all plugs out. test each cylinder. They shouldnt change more then 20%. if they do, you have a problem. Crank the engine for about 5 'whines' each cylinder but keep it the same amount.
Then if you have a cylinder low on comp, squirt a little oil into the plug hole and re-comp test. this seals the rings. so if its still low its a head problem, if it raises its a ring problem.