I agree with Shane, I think the normal operating temp for that engine should be 195 degrees, so 190 to 200 should not be a problem. Having said that, with your high flow water pump and thermostat, thermo fans, etc, the temp should be lower.
Comments:
1. I think your problem is restricted air flow, vertical fins (radiator) and horizontal (intercooler) causes restricted air flow. How strong are your thermos, I would be looking at least 2800cfm but 3000cfm would be better. You could also install an intercooler fan.
2. The small heat exchangers, what are they for - transmission/engine oil coolers? B&M do small ones for big engines.
3. I would set the thermos coming on at 180 degrees. Do you have mechanical or digital or other thermo switch? Go digital or better.
4. I presume the Holden HQ radiator is an upright, if you are looking to change, I would consider a thinner cross flow, with the radiator cap on the lower pressure side. These are more efficient