Well, if this is your first venture into mining I would advise you to start small, build 1 rig and learn the process, after it's running 100% stable for a week build the next one, etc.... 8 at once may be difficult at first.
I think what you said is through starting mining in a little ways will give you time to learn how mining really work in a practical theme and also it will enable you to easily current your mistake without mush financial cost then from there one can expend little by little.