Currently of the 3 things you mention, only the disk drive can be upgraded.
[you have to use 9mm slim laptop drives too as 12.5mm drives won't fit].

And then you have to find a way to upgrade to software externally to the progear - e.g. via your PC.


If you get it cheap enough its a good deal. I have one, that works fine.

Ditch the Linux on it though as its out of date.
I put Win XP pro on it and it runs fine once you stop 2/3rd of the unneeded windows services.