SIMPLETHINGS

Hey guys. I finally got an 520STF super cheap with a monitor out of the blue and have always wanted to set one up for Cubase like some of my favorite artists from the 90's used. After doing some research I'm not sure if I should spend money upgrading my STF or just wait for an STE. I'm aware that I can upgrade my 520STF to 4MB of memory, I was looking at a nice kit someone it selling in the UK. Are the enhanced graphics capabilities and sound capabilities of the STE used by programs like CUBASE? Another question I have is if Cubase can use any of the ST / STE's on board sound for sequencing or if it is all external MIDI only. Thanks for any help in advance guys!