how are you planning to run all of this? do you have a (or a few) multi channel amp(s) to devote the adiquate power to these speakers? have you thought about what crossovers to use? soem of my favorite mid-range speakers include the image dynamics chamelions, the a/d/s 3-series, and the pre 1999 diamond audio hex series. there are others, such as morel, kefs "kar" series, and nearly anything by dynaudio that are great but will be hard to find/afford.

the key to great midbass really relys on the way they are installed. if you are planning on putting them in the doors, make sure you completly seal the rear wave from the front, meaning you should block all the inner door holes with wood/sound dampener/etc. you might also have to sound deaden certain parts inside the door to keep them from rattling (such as the door lock levers), especially if youre running a high power setup.

your best bet is to go around to audio shops and listen to what they have, then make your desicion from that. all the speakers i mentioned above tend to have a very organic, rich, and deep sound to them, as it fits the type of music i tend to listen to and the sound i enjoy.