You'll have to watch your case choice with the CM V6 GT. It's 165 mm tall. But it does cool well.Cooler Master V6GT CPU Cooler Review
The Corsair H50 or H70 are sealed unit CPU watercoolers that are easy to install and have no maintenance. Corsair Hydro Series H50 CPU Water Cooling Kit ReviewCorsair Hydro Series H70 CPU Water Cooling Kit Review
When you get right down to it any of the top CPU coolers should be good enough to let you get top overclocks out of your X6 1055T - what ever that might be.