Lots of good information so far. Thank you.
I really also would need some advice regarding the other part of my question - connection used.
As I stated I am using a PC with USB 2 / 3 connections and I have a firewire 400 too.
I could potentially also install a Thunderbolt card as well but some people say it can create problems with the PC.
Firewire is apparently much more stable for audio than USB but new cards using USB 3 are supposedly better.
For me I would like to be able to work as stated before with low latency and for example USB 2 apparently is not ideal (also considering if you want to be working with lower buffer sizes).
USB, Firewire or Thunderbolt?