Looking for a 5.1 sound fix

Title basically says it all. I want to fully enjoy my PS3 with 5.1 sound. Now I mean I could but some cheapo speakers and hook it up with the L/R jacks, but that's not what I want.

I was looking for computer speakers that had SPDIF In but I guess they do not make those or I just could not find any. So I went to look at home theater systems and the ones that did offer it were a bit out of my price range.

So I looked at some sound cards that SPDIF In. They were in my price range. So I'm thinking, buy one of those, a decent set of 5.1 computer speakers, and then my problem is fixed right? Has anyone ever done this before? How well does it work if so? Or if you know of a set of speakers that I was looking for earlier that would be great.

Thanks.

I have klipsch quintet speakers and a 10" sub hooked up for my tv etc. I connected it to my computer via a digital optical cable to a dynex 5.1 sound card. Works wonderfully.
However the speakers are $500 and the sub is $200-$250. You can find cheaper stuff of course but all you have to have is a AV receiver.