First off, a deck will never really produce anything more than about 20x4 watts rms (max is a useless measure).
Plus, it's "dirty" power with lots of THD and not much amperage.
A nice outboard amp rated at a measly 25w rms will sound light years better than any deck.
BTW, I wouldn't run a set of components off the deck. You'll be very disappointed in the results.
At best, a deck is good for some inexpensive, efficient coaxial speakers as "level 1" upgrade over stock.
