The PSU is already covered, as is the case - I know some people at a
community center that have a plethora of cases either empty or with
non-working motherboards, and they're willing to trade me a tower that
should support whatever board I buy, and seeing as this is a standard
ATX board, I don't see why that'd be a problem (this isn't the first
time I've switched the board out of a system) - even if I wanted to use
the same case, all I have to remove is the rear shield, and replace it
with the one that'll come with the new motherboard. Case I have is
already set for the ATX form factor - most of the reason I'm replacing
it is it gives the community center some working hardware without them
having to strip too much out of an existing system to put new stuff in
(and it means that I won't really have to change out boards, just throw
it in a new case and all that).

I think the word "Upgrade" might be misleading; I say it because most of
what I have NOW I'll be using. However, most of what I have NOW is not
part of the original system - none of the drives, save the CD Burner
are. Neither are any of the expansion cards, aside from the display
adapter, which, as I've already said, is going to be replaced. Pretty
much by the time I'm done getting the parts and all it'll be like having
built a system from scratch, since the only part that was originally in
the system when I got it, and will be moved to my new system will be the
CD burner. I honestly fail to see how not changing out a CD-RW drive is
the same as just adding a new part to the board and expecting it to be
faster. This isn't me adding some new adapters to the system and
expecting it to be faster; I'm not buying a processor for an obsolete
chipset and expecting blazing fast performance. I'm replacing
EVERYTHING - case, motherboard, processor and all. I ask the question
about what I should do because it'd be like taking the hard drive from
one system to another and expecting it to boot, and I want to know,
before I switch everything out, whether it'll be easier to try setting
up the system for the new hardware, or if I should go ahead and just
wipe the OS and start over.

I ask the question about upping my performance because I have to still
use my current hardware for another month or so, and, especially with
the idea that I'll have a faster computer soon, I'm getting a bit tired
about how slow my system is.

As to buying a bargain basement system, something that's $4-500 is not a
deal for me. At current I'm looking at less than $200 to get my system
in order and pretty much have a new system that'll last me for a good
long while (for example, I'm looking at a motherboard that's got both
PATA and SATA support, allowing me to use my current drives as well as
upgrade to SATA later on; it's using Intel's LGA775 chipset so I have a
nice wide range of processors to choose from if I want to upgrade from
the dual-core I'm getting). My feeling is that the prebuilt systems are
going to have hardware that I don't want or need, since I have enough
up-to-date hardware in my system at current to where I no longer have to
buy that much to have a good system.