You're going to get a variety of opinions and feedback. There's a thread in the general section already about driving on 20s that might help you. I love my 18s, check out my profile if you want to see them. They are 18x9.5" with 275 Nittos on all four corners.
Since you did ask for opinions though, here's mine
I chose 18s because they are better for handling at the limit. They offer some warning before they let go, unlike something bigger, which will offer no warning before they lose traction. My 18s are lighter than comparable wheels as well. They also clear my Brembos. A wheel with a bigger diameter (where more of the weight is toward the outside of the wheel) is going to take more effort to turn than a smaller diameter wheel. Since you are drag racing, I'm just going to go ahead and say that I don't think you should have 20s on the car, period. There are folks who successfully drag race on their big wheels, but I think they would be even more successful with smaller ones. If you don't want the wheels inside the fender, you need to look at the offset. That'll determine how far out they stick.
Frankly the little rubber bands on 20s just look wrong on American muscle (in my opinion). I am in the boat that anything bigger just look like wagon wheels and that you are all show and no go.
For reference, Ford equips their race cars (such as the Boss 302S and 302R or FR500C) with 18s. Some people think that just because a GT500 or Boss 302 comes off the factory floor with 19s or 20s, that must mean that's the best choice, and that is simply not true.
At the end of the day though, the only real thing that matters is what YOU want and everyone else be damned.