You want additional speakers in the rear doors? The sound wont be good unless you put a good sound system. Basic 1.3 manual city comes with a useless CD player, so better stick with front door speakers only.
If you want to add rear speakers, dont go for Honda speakers as they are only bassers. Go for aftermarket speakers Pioneer or Sony. Move the front speakers behind and install new ones in the front.
If you really need good sound without a stereo then move front speakers behind and install Sony component system in the front. Cost ~ 10K-12K