2006 WRX TR Sedan Audio Question

[Salvation27]

Fellow audiophiles-

Looking to finally upgrade the audio now that I'm mostly near where I want to be mechanically.

I've read the threads- 6.5 all around with special spacers, or 6.5 with 5.25 in the back etc.

Here's my question(s):

I was thinking 6.5 all around with an amp supplied to all (4) speakers. Having it installed as I am not that savy nor do I feel comfortable ripping my baby to shreds haha.

Best speakers nowadays?
And where are these spacers I'll need? I've looked- most links are dead.
Don't flame about reading- as I have.
I just wanna buy the parts, with spacers, bring to installer, and make it easy for everyone.

Thanks for your help!

PM if you have anymore ideas/ better ones, etc.
Or just shout them out here

And if locked for "research"- just post the link here so I can jump right to it