5.1 in 5 or 7 thousands, hmm, those cute little bunny speakers?
If you are an audioholic like me then get something that has loud-speaker, mid-speaker, low-base speaker, tweeter and also get a nice amp. I got Pioneer's speaker set (don't ask for price). They are original Japan made (I asked my friend to bring it when returning from trip). The sound from my computer goes into amp and then distributed to speakers. Yes sir, that's my personal desktop computer, not my media PC I admit, I am audioholic
Otherwise, any good manufacturer's small size good speaker will work. Usually speakers of that price range give somewhat similar sound output Even you want small desktop speakers, I shall suggest to get some good speakers (like original Sony).
Computer responses with monitor (sight sense) and speaker/audio (hearing sense). These are two most used outputs from a computer. Therefore, monitor and speakers should be good because we use them to get output from a computer. It's similar to have a good keyboard and mouse as that's the way we communicate with computer.
Good speakers let's your computer to communicate better with you. Good luck!