To me the ideal spot is in the corner on the west side of I-4 at the 408/I-4 Interchange in the spot south of CityView/Huges Square. The view of downtown coming in from I-4 from the southside of town would be unreal with the development downtown on the east side and a new stadium on the west side.
The only downside I can see to something like that is what people have mentioned on this board about how the stuff that is on the west side already acts as a barrier to development and my proposal wouldnt help that at all, it would just be really aesthetically pleasing.
In the end though, if the city is gonna have a world class facility, then I am all for it wherever it is!!