So you have properly bled the system and refilled with 50/50 coolant, installed new water pump and oem t-stat, verified you have good flow/circuation thru the radiator, cooling fans that come on at the right time(before the temp gage passes 1/2 way).

If you still have the temp gage reach near the red mark and you are confident that the engine is not actually running hot or close to overheating, I would replace the temp sending that reads to the temp gage. Definately use an oem honda part. There are 3 or 4 temp switches on that car, be sure you are replacing the one that goes to the temp gage.