The plugs are moved putting them in the way of the std. flange that most headers have. You need to cut the flanges and only use the tube/flange that fits on the head. The inbetween flanges have to be cut or they will not allow sparkplugs to be installed.
Eddy heads don't really suck....just depends on the application. There are a few out there running in the 9's with them in 3000lb. cars!
I recommend doing alot of research on those heads before settling on them....