I've been running resistor-less COPS on my '85 for years now with no problems. That doesn't guarantee that your TCI box won't fry, or that mine won't go up in smoke the next time I start the engine. But, if it hasn't failed yet, I think it probably won't.
As far as what coils to use, I just bought 4 coils off EBay, not knowing there was any difference in them. This was before people were adding the resistors. I think mine came out of a Suzuki GSX-something..
Cost me about $25.00 to make up my set.