I want to go to coil overs.. I have 19 inch wheels on it now with a 1.25 inch drop with lowering springs... Are coil overs better? I'm just worried about the turning and rubbing issue... Advice?

 

Or can I go to a 20inch wheel? I want a more aggressive stance and lower to the ground..

 

The only way to get lower is with coil over (or air ride).
Stance is about width and offset. You can do 20" wheels if you want.
I run a 20x9 et30. People go as wide as 20x10 et40 with a square setup.

 

Even if I have lowering springs? I can still go with a 20?

 

Yes. You get lower profile tires so the outside diameter is the same.
You have to make sure they have the right offset, so they don't stick out past the fenders or there is a good chance you will rub, that applies to all aftermarket wheels though.