first time posting so forgive my newbie antics, i was wondering what aftermarket headunits you guys have? any tips on what to look for when replacing the stock unit and speakers?

 

Welcome to the forum.
Any single DIN headunit will do. Try researching at crutchfield to find out what fits well for speakers in the doors.
Hmmmm best advice for stereo ...
Skip replacing the rears focus your cash for a nice two channel amp for the fronts so you can get into some nice front speakers.
$200 for head unit
$150-200 for front component speakers
$100-150 for a two channel amp
$12 for a wiring harness
$20 for a mounting kit
15 ft of 8 gauage wire for the amp
and about 175 to have it all installed unless you do it yourself which I would recomend so you can spend more dollars on the gear.
Run the rears of the power from the head unit
As you want more, you can add a sub and another amp (if you think you might crave the base later on use a 4 guage power wire from the battery back to your amps)
I started my stereo with a Clarion single Din DX745 (think thats right). I upgraded to an Pioneer Avic Z-1. Best purchase since the Z!

 

I have a Pioneer DEH-P6800MP head unit and LOVE it. It really all depends on what YOU want when buying a head unit such as navi, dvd, mp3, and other capabilities.

If you plan to put subs in your car then look to see if the head unit has tunable options. (basically the more the better)

And when replacing speakers it also depends if you want more bass or better sound quality, or both.

 

Pioneer AVICN3

 

I just got the Alpine CDA-9856 $199.99 buy your headunit at crutchfield and get the install kits free(wiring and dash kit). If you're a new crutchfield user you can save 20 bucks using my referral code pyph0-xj4sq-5qvgg

mb quart R16 components at carstereo.com for 135 (made the mounting rings work no extra spacers needed

some pioneer coaxial 3 ways for the back for 50 bucks

HIFONICS ZXI8006 750W 5 channel AMP for 239 from carstereo.com

 

Pioneer AVIC N2

 

Excellent suggestions. If you're going to run power cable though, I would suggest starting with 4g just to prevent having to re-reun when you get a sub or bigger amp.

 

I'd suggest finding a HU with three RCA outputs. It'll just be easier in the end. The Alpine 9856, like schwank has, will let you independantly control your rear (sub) channel's output.