Used is your only option for the best sound... that is unless your friend at best buy hooks you up with employe cost???
If not I would go to Car Audio Classifieds - DIYMA.com - Scientific Car Audio - Truth in Sound Quality
& buy your stuff there. I purchased my Hertz Mille speakers (ML1600 & ML280) & x-over there at 35-40% off retail & they were new. I also purchased my Morel Ultimo 12 SC from someone on the site for close to 30% off BNIB ..... I want SQ so I did a bit of research there which led me to the stuff I have sitting in my garage waiting to be installed.
The used stuff I just purchases is all used but in great condition. Alpine W910 deck & Alpine DPX 1000.1 amp. I paid $250 for the 1000w amp.....
Many over on the site have a lot of great things to say about Massive speakers... I do not know what size fits your car, I did a 6.5in component set for my viggen.
Sub wise I think it depends on how you want it to sound. SPL, SQL or SQ?