The WotC virtual tabletop is probably going to be your best bet in terms of integration. The problem is that when I say 'going to be' thats definitely future tense. As far as I know none of the integration is done yet. The cost will likely also be a sticking point, I suspect that it will be attached to their DDI subscription which makes it a monthly fee to use.
Fantasy Grounds has some integration, but I've never used it. From what I understand it will give you a full character sheet that you fill in. Once thats done it will calculate the modifiers and make all your attack rolls just take a button click. I've never actually used it so I can't say for certain. At the time I wasn't about to pay $25 just to see how it works.
My personal choice is MapTools, as far as I can tell its mapping abilities far exceed anything else out there. That said, most of these features are overkill and not used very often. Its scripting features are also pretty awesome and allow you to create the same forms that you would get out of Fantasy Grounds. Fortunately some folks have already built macro frameworks to take care of this for you; for example this one. Again I haven't used those, being a bit of a computer geek I decided to make my own which I'd be willing to share if you're interested.
If you're ok with paying for the integration in Fantasy Grounds, then go that route. It ought to be ready to go straight out of the box and cause the least hassles. If you don't mind fiddling around with the MapTool macros and frameworks then they might be worth a look. Seeing as how all the MapTools stuff is free anyway, you might see how daunting that will be before buying Fantasy Grounds.
I suppose once WotC finishes their tabletop it'll be worth a look as well. Since it'll import characters straight from their character builder, you won't be able to get much easier in getting everything built and ready to go. The real sticking point will be how they price it once its complete.