msd or mopar hei ?

totally confused, i`m looking for info on the msd products. right now i have the chrysler after market ignition (chrome box) on my 440 that we have done up. eddy`s, big cans, crane roller etc.etc. once in a while, down the track. i`ve had several people mention to me that i`m better off with this set up than msd. i was all prepared to start buying the msd parts and now what? well, i decided to do the best thing i know and through out to you guys. i`m sure someone in this family nows best. help,please and thanks