Building your own should not require any soldering .. unless you are doing it wrong.

Everything plugs together. Just make sure you have the right piece to plug into the available slots.
In other words; get a motherboard with the features you need.

I usually get a motherboard/cpu combination (make sure it fits the available case).
Make sure it has available PCI, PCIe, or whatever, to fit any of your needs.
Lots of USB connections is always good.
If it comes with a good amount of RAM, even better.
Hard drives are not expensive.

The way I look at it is
I have an acceptable case (save $$)
I can re-use existing hard drive if needed (may have to re-activate Windows due to new machine key) or clone it to new drive and use the existing one as an 'extra' for temp files, development/testing or whatever. Not relied on for anything critical because it's old, but usable none the less. Also could just be a backup copy of the OS at a given point in time. (save $$)
The above has value, plus, like I said above, no bloatware to deal with.

Just make sure everything fits and will play nice. If you have a DVD drive you want to re-purpose make sure you can accommodate it.
A good case can last many years; I lucked into one due to my job, and grew to appreciate it over time. It can fit many size motherboards, multiple hard drives (8), different size power supplies, and has the space for extra standard size physical add-on devices (DVD, card reader,etc).
If you don't have a good case to work with, it is worth investing in a good one in my humble opinion.

Guess what I'm saying is, it takes planning, but shouldn't require any soldering ..
All I was implying in earlier post, really, was that if you buy off the shelf, just clean all the junk off the system first thing. I prefer to do that before creating any Restore or Repair or Image Backup disks .. so I don't ever have to do it again.


I do not work here, but the benefits are still awesome
Make your sound your own!