I think i know which ones your talking about chevelle and hoestly i wouldn't waste a penny on them things in my opinion

the eRAM style if i'm not mistaken if thats the kind your talking about is designed for cars such as toyota and other ricer style cars and even then they only "claim" 7-13hp gain and honestly i dont even believe that myself.
My advice at your age i'd build a good solid nat. aspirated motor and wait till you can afford a true supercharger such as Weiand,BDS,or the such and do it right without wasteing money on "gimmics" ...at least thats my feelings on it.

BG