How many channels

Hello everyone, pretty new to the forum but not a complete noob in car audio. I just had a q 12 installed in my EXT cab f150 hooked up to a hifonics brz17001.d. Unfortunately the brz is a faulty amp(not surprising) but in the process of getting a replacement.

My question is to balance out my sound stage I am going to be putting in 4 new infinity kappa 5x7s(not set on them open to suggestions around the same price) and was hoping to throw a pair of tweeters in too. I was wondering should i go with a 4, 5, or 6 channel amp.

I understand that if I want control of the fade and balance I need a 4 channel for the door speakers. But should i wire the pair of tweeters to the front 2 speaker channels( i assume that would decrease the power going to the front door speakers.) or wire the pair to their own channel with a 5 channel. or wire each to its own channel with a 6 channel. I did a real quick search for 6 channels but didnt yield much. I would like the amp to be an alpine if no one has a reason for objection.

I currently have a mrvf305. which i dont think is going to power all the new goodies very well.

im a little low on cash after the install and all so im not in a rush to get them right now. and honestly i think im gonna have a viper 5901 installed before the speakers, but i like to know what i want.

thanks in advance