Try Royal Caribbean - great kids facilities, or alternatively P&O. Go for one of tth larger ships as these have more facilities e.g. RCI have kids clubs, kids pools, mini golf, rock climbing, surfing, ice skating etc
One word of advice - check out the ages for the kids clubs. Some have broader age ranges than others (not always a good thing) Your 2 boys may want to be together, in which case you will need one catering for 6/7 to 12 or they may want a closer age range with activiites to suit their ages. Our 6 six year old was adamant he wanted to be with his own age and not with the "babies" so we chose one with clubs for 5-7 or 6-8 rather than one for 3/4 - 6 - hope that makes sense!
Take it from me you wont see them at all during the cruise, they are too "Busy"!!
they go to the childrens centre and thats it for the day! its lovely and they love it as well.
we did take walkie talkies with us to save running here there and everywhere..saves your legs...but they were fine...They even went for meals together.....Go...you and they will LOVE it.... A.