av receiver help needed

hi,i have narrowed it down to the harmon kardon avr354 and the denon avr889, i am using infinity overture 3's, 8 ohms 94 db for the fronts, infinity cc3 center speaker for the center and two infinity cc3's center speakers for the rears, which receiver do you think would sound the best with the speakers that i have, i currently have a 6 year old onkyo TX DS575 the first onkyo available with pro logic II 75 watt per channel running the system, would there be an improvement in sound with any of the above mentioned receivers or should i buy another onkyo the reason i ask is because i have read that onkyo was kinda on the bright side, any help would be greatly appreciated.
thank you