Go to Advance Auto and ask for your cars year and Model and get a metro kit i got one for my 91 civic but it did not work so it also for a 94 civic so once i start on my system in the acura i will already have a kiit. all i will have to buy is a wiring harness. I have learn if you don't have a lot of spare money, do it in stages stage (1)
buy what you need deck, speakers, amp, subs, then stage two get wiring harness etc, you can do it any way
you want just remember to do it in stages, that way you can afford it.