If you were to do a search [perhaps in review section ] for : TS-C720PRS 
YOu're better off using more power than less.
At least you can use the amp for something else if you decide to change the system.
I always like to have amps that can be used for more than one thing.
I'm with both of these gentlemen.Mark Eldridge once said "power is like money in the bank. It is better to have it and not need it than to need it and not have it".
I'd go with as much power as you can afford on EVERY driver. Worst case, you don't use it.
I'm got 350 watts available for my tweets.