alpines mid bass kit

ok i was looking at getting some compenots speakers for my car and i found on alpines website that they have a mid bass 6.5 kit and what i was thinking was how good it sound if i had them at my rear and still get normal compenots for the front ( i have 6.5 all the way around) since also i read on here that you can get away with regulaer coaxials in the back since the subs would hid the coaxs sound. oh btw the rating for it 75 wrms and 150 peak i belive.

and any info on the alpines type x comopeonts?