Geometry of that bike is sort of old style vintage steel bike. (horizontal top tube)
Even at a 58 cm it might be too big for you. But the position of the STI's on that bar will never be comfortable to me. I'd go more with what
Carbonfiberboy shows and that is going to require a different drop bar profile. You might look at short reach drops while you are at it.
If you think you need to have higher bars, then also look at riser drop bars. They can get you 1 to almost 2 inches higher on that stem you currently have. But you might also need a shorter stem. So who's to say. You just need to spend more money! Even old bikes that seem inexpensive can quickly cost more than a new bike.
Adding steerer tube extenders and overly angled stems to your bike will just make it look gross to me. I'd sell or throw away any bike I had to do that to. I don't really like the look of bikes with stems that are much from horizontal. But I know that is just my personal likes and dislikes and doesn't matter for strictly fitting purposes.