Sound blaster will do fine.
I do not know how much you know about cubase. It might be a tad complicated especially the finer in depth functions. A good suggestion for simple recordings is Audacity it is very easy to use compared to cubase and has some neat edit facilities and fx plus it is downloadable free. Once you have mastered the basics you can then progress onto the finer points of cubase. Just a suggestion.
Re speakers I use Creative and would not swap them for anything else I have heard up till now.
Re interface. another alternative is some of the new age mixing desks that have built in firewire or usb connections etc. Try Mackie or Alesys. You may look on a desk as an investment as you can use it for live performances as well killing two birds with one stone. If you go for a mixing desk I would recommend a passive (non powered) one that has more imputs than you currently need saves upgrading.
Just saw your pics. The cowboy hat is the one that works the best.

http://www.soundclick.com/bands/songInfo.cfm?bandID=687727&songID=5238055