What kind of speakers for my 94 camaro?

So i bought this 94 t top camaro and the guy i bought it from had a custom setup in it so he took it all out besides the two front door speakers which are some pioneers. So i want to use the stereo i have in my old honda so i got some questions
Btw crutchfield says 6.3/4 fit in my backseat and trunk i believe.
So my questions are
1. What do i need to buy to use my hondas radio in the camaro
2. My friend hes these speakers he wants to sell me for 100 bucks heres the link http://www.crutchfield.com/p_049RCE213/MB-Quart-Reference-RCE213.html?tp=106&%3bamp%3bamp%3bamp%3bamp%3btp=106&MobileCarSelectorComplete=1
So would these work what would i need to make thwm work?

3. Does it matter if my speakers are all difeerent?

Im not very smart in this subject so pics links and good explinations would help thank you.

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