$450 is a little slim imo, I figure you're going to want about $100+ fo
each item

Deck: $200 I would highly recommend Alpine
Sub: about $100
Amp:  $100 plu
Speakers: $100 plu
Another amp: $100 plu
Wire: $10

Size and space, not sound quality, should be the only reason to limi
yourself to a 10"

--
John

Head unit:  There are good head units all around that have good sound
quality.  I suggest you go to

http://www.crutchfield.com/

If you are going for quality, you probably want a good start by buying
a good head unit that costs at $ 150 and above.  Again, look at the
reviews from Crutchfield and read all that you can.  What do you want
on your head unit?  What color do you want it to be?  etc...

Speakers:  If you want quality, I suggest that you replace all your
stock speakers with decent after market ones. A subwoofer will bring
out bass but it will not give you clarity in your sound.  Alpine are
known to make good quality speakers... check these out for example:
http://www.crutchfield.com/S-ECUu8KxqR9u/cgi-bin/ProdView.asp?g=52000&I=500SPS17C2

Component speakers are more expensive than full-range speakers.  If
you are going cheap, I suggest you stick with 2-way, 3-way, or 4-way
speaker designs.

Amplifier:  Again, look around and see what you like... if you like
more power in your midrange, I suggest you get a 4-channel amp for
your after market speakers.  But if you want your midrange just so you
can hear it, I suggest you don't get one.  For a subwoofer or two, I
would get a 2/1 channel amp for under 120 dollars.  Profile seems to
make some decent ones for around that price.

Subwoofer:  Do you want your car to rattle with bass?  Or do you just
want bass for a better overall sound?  If the latter, I suggest you
get an 8" subwoofer and at most a 10"... Kenwood makes some "weak"
powered ones that are good quality.

Wires, Harnesses, installation kits, and baffle materials... : I
suggest you save at least 200 dollars for this...

Altogether if you want good sound quality you are going to have to
spend at least 500 dollars... No way to get around it really.  If you
are an ebayer, I suggest you try to find cheap deals from there and go
to crutchfield for information.  Indoaudio is a company on ebay that
sells relatively cheap car audio products... so far I hadn't had any
big problems with them.

i think he means that  $450 is the most he is willing to spend on a
headunit?
at least that's how i read it, anyway.

and i also think what he means is, that it really doesn't matter how
much he spnds on speakers.
again, that is just how i read it.

My recommendations/$.02:

Interior Speakers:  I won't go into the interior speakers too much -
except to say that despite what some people will tell you here (braces
for flaming) amplifying your interior speakers is not always
necessary.  For a long time I had an amplified 10" sub (usually around
150 watts rms) with the interior speakers running off of the head
unit, and it sounded fine (good, even).  You may want to upgrade
later, but to save money in the beginning you can run the setup this
way.

Head Units:  Alpine is well respected, and you'll be hard pressed to
find many people who talk badly about them - I have a Panasonic, and
love the features, but it's not durable at all - I've also heard good
things about Kenwood, except that in order to plug in auxilliary
inputs you'll have to spend extra on adapters and whatnot.

Amplifiers:  I 100% recommend JBL amplifiers.  They are consistant,
underrated (power-wise), reasonably priced, cool running, and exceed
my expectations.

Subwoofer:  I too am a 10" fan.  I like the way a 10 sounds in a
ported box, when compared to a 12" sub anytime.  I have a JBL GTO
1004D, 10-inch Dual Voice Coil Subwoofer in a custom designed (and
built) ported box tuned to 27 Hz.  It is the best subwoofer I've ever
owned, so I have to recommend it to anyone looking for a
recommendation.

If any of that helps, then I've done my job.

~Mister.Lull