Your answer may be basic but it went way over my head!
What's an SSD drive? Most PCs come with 500GB or 1TB hard drive space so I won't have to worry about that.
SSD stands for solid state device. These hard drives are made from memory chips only and therefore run silent, cooler and a lot faster than a standard (SATA) hard drive. The larger disks you mention are fine for storage but the trend now is to have the operating system on an SSD and in your case carry out the video editing within software on the SSD. Why? Cos it's faster.
No idea what SATA HDD is.
It stands for Serial Advanced Technology Attachment Hard Disk Drive but all you're concerned about here is the letter 'S' - it stands for 'Serial' and denotes the way the data is transferred to and from the hard drive. Older hard drive technology was PATA (also known as 'IDE') where the P stood for Paralell. They were slower than SATA drives.
Even if I were to look for a PC with the spec you defined, how easy is it to find one ready built on the high street or must I get it over the internet, custom built? Not too keen on custom as I've heard it's possible the different parts, once assembled are not that compatible, owing to different manufacturers.
Try a local dealer for a quote to put one together for you. Print out the text of this thread and show them and ask for comments, you should soon be able to determine whether they are trustworthy or not.
It's a much better option, usually, than buying from the big boys. A company called Novatech are good for ready-made machines, look 'em up, have a browse. Incompatibility between parts is rare and it's a myth to think otherwise. Providing the CPU matches the motherboard socket and also the RAM (Memory) matches (it's almost universally DDR3 memory right now) then there should be no probs.
Do not be talked into buying a seperate graphics card (except for gaming) there will be no advantage for video editing or, indeed, video playback, the i series of Intel CPU's have all the graphics capability you need.
If you can find an example of one already, eg Dell, HP, etc. that'll be great.
You're free to go down that path if you wish of course but mostly the likes of Dell, HP etc are greatly overpriced. And oddly enough when you talk of incompatibility these are the worst culprits, if you want to upgrade one of these machines in the future the parts will have to be Dell or whatever compatible or they may not work with that machine. And guess what? Dell or whatever compatible parts cost more.
Hope that clears up any confusion.