Can I do this?

I have a 68 convertible and want to put in a decent system. I have two 10" subs that I will put in a custom box in the trunk. I have speakers to put in the kick panels (pods) and deluxe door panel speakers. I will be running two amps, one for the subs and one for the two other sets of speakers. My question is can I run two 3.5 - 4" speakers that I run straight off the deck in the original dash speaker location or will I stress the deck out too much? I haven't purchased the deck yet but I will look for one with 3 preouts and at least 50w.

I am going to run two amps. One for the subs and one for the kick panel and door speakers. Sorry I wan't clear on that. I am thinking about running two more small speakers in the dash speaker location. Can I run that without an amp and only on the head or will it cause more problems then it is worth?