I run 4 T162C RF coaxials in all the doors (i run coaxials cause im cheap), it runs off a T3002amp. I also have a T1 sub, and it runs off a T5002 amp. Do i need a equalizer. I dont know, because i dont know how it works.
Do you have a good headunit with more than a 3 or 4 band eq on it? You of course need to run crossover's to the spakers first, then worry about an eq. It's not absolutely necessary as long as you have filters, but it'll sound a lot better if you have an eq.