Im deciding on how to proceed with building my 1st gaming PC. I dont plan on storing alot of music/pics/movies, just mainly playing games. So do I need both an SSD and an HDD or can I just get a larger SSD (ie. 250gb) and use my existing 1TB external HD for whenever I do download the occasional movie? Thank you
SSD's are nice and fast so as long as you can get by with your files/programs on the SSD, go for it.
As with any drive, keeping a backup of personal files is ALWAYS a good idea. SSD's and HDD's can fail.
I personally have a 256 gigabyte SSD for Windows another for some extra programs/games a small 64gigabyte SSD for Win8 and 2 TB drive for files/documents/desktop/ect. I have another identical 2TB drive in an enclosure for backups(on for backup, then off to keep it as an offline backup so to speak.).
That is what I would do. You may only need 128GB SSD if you are only using it for games and the OS. If you intend to use software on it too though, I would go with a 256GB. You will love the speed at which games load on an SSD!