New 370z owner / Audio upgrade suggestions needed

[Stapel65]

Greetings gents,

Just joined the forum today after purchasing my 370z a week ago. Honestly, I have to say that you all are awesome for posting this wealth of information. I'd been logging on anonymously since I bought the car and don't know what I would have done without all your help. From that mysterious engine smell the first few days of spirited driving to questions about oil temp, you all have saved me at least a few trips to the dealer.

Anyway, I'd like to ask your options on an audio upgrade I'm considering. Since I don't have any experience with this type of thing I'll be depending on outsiders advice and an installer. I went to a local shop today and got some decent sounding advice but I'd like your opinion. Here's what I'm looking at based on today's research:

Diamond SXP65s 6.5'' Component system for front door and dash tweeter
Wicked CAS Corner sub box "magicbox"
Rockford Fosgate 10'' shallow mount P3SD4-10
Rockford Fosgate PBR500X-1 Amp
Replace HU with either Kenwood DNX5190HD or DNX7190HD

I guess my question is around value. Do you guys have suggestions as to if I could save some coin and keep the quality or up the quality for a similar price?

Also, the installer suggested that we could install the tweeters from the diamond system in the door right next to the 6.5'' and use the dash space for another, larger tweeter/mid-high. Thoughts?

I wasn't planning to use the rear speaker ports and they are not currently wired. I've got the base/sport model.

Thanks!