Mac mini (Late 2014). 2.6GHz. SSD Options.

Howdy,

I've been thinking long and hard about upgrading my internal 1TB HDD to a 1TB SSD. I've read all the guides etc and out of warranty. My one question is, on Apple's Tech Specs (http://www.apple.com/uk/mac-mini/specs/) & (Mac mini (Late 2014) - Technical Specifications) the 2.6GHz model only has the following options:

• 1TB (5400-rpm) hard drive
• Configurable to 1TB Fusion Drive
• 256GB of flash storage (SSD)

So my question is this. Are those the options that Apple Engineers can perform when customising the Mac Mini during a purchase? Am I still able to upgrade to a 1TB SSD or higher, knowing I'll void the warranty? Or take to an Apple Store to install for me? Basically, those above options, are they set in the O/S or Firmware physically preventing an upgrade outside of those choices? I don't want to buy the 1TB SSD and find out that the system won't read the drive :\

Thanks in advance