Adding more drives isn't a big issue. I don't see any need to move computers unless you just want to. Personally, I like having ALL of my systems edit-ready, just in case work overflows and I need more space to process/etc.
You do NOT want your operating system (Windows) to reside on the same drive as your videos that you're working with. Most OS, especially Windows, use temporary hard drive space for temp files, cache, swap files, virtual RAM, etc. All of that I/O on the drive will interrupt the flow of video data, as well as help to fragment the video data. Neither of those is good. It's best to dedicated a drive to Windows and programs (or other user files like Word docs, MP3, photos, etc), and then use a separate drive for your video work.
A 1TB drive is probably fine. If you want great deals on hard drives, there are only two places I suggest:
Geeks.com for online shopping, or Microcenter (or Fry's) for in-store local shopping. Some people like
Newegg, but I find them to be overrated and often overpriced.
Amazon has good deals from time to time, too. (If you're shopping around, be sure to use
our links, if you don't mind.)
There's nothing wrong with refurbished hard drives, FYI. I buy them all the time, no complaints here. I've had worse luck with "brand new" drives sold online or in stores. I bought about a dozen drives last year, mostly refurbs, and mostly from Geeks or Microcenter.
As far as adding a SATA drive to the system that has run out of SATA ports...
All you have to do is add a card. I asked you a lot of questions, trying to decide what card you really need, as there are quite a few options.
However, I just now came across this card from Promise:
http://www.amazon.com/gp/product/B00...SIN=B0032GPZPO
Promise is a well-known name for expansion cards, be it IDE, SATA or RAID (or all of the above!). This exact card has two internal SATA-II (3Gb) connections, an IDE, and an external eSATA connection. This card is a new product from Dec 2009, and did not exist when I put together my last system in July 2009 -- I wish it had!
Prior to finding that item, I had been looking at these:
The promise is the cheapest, fastest and has the most port options. Unbelievable. I'm tempted to buy myself one, and toss out my current card. (But I won't, because I' m too busy to tear apart the computer.)
Hope that helps.
