logitech z5500 vs klipsch promedia ultra 5.1 vs gigaworks 7.1 s750 ASAP!!

So the time to upgrade has arrived, my old cheap logitech 5.1 unit has died and i dont want a 2.1 due to some games i play.
The few im looking at are:

Gigaworks s750 7.1 w/ DDTS-1000 encoder- $350 across town
Klipsch Promedia ultra 5.1- $300 across town
Logitech z5500- $250 but 3 hours away
Logitech z5300e- $60 maybe 15 minutes from me!

I'm running a sabertooth Z87 Mobo with no soundcard at the moment and hoping i dont need one, my office is 12x10 without furniture lol and i have places to put a 7.1 if need be. I play mostly games like skyrim etc and listen to music and some youtubage, i do not mix sound and i have a huge home theatre to watch movies on already.
I keep going back and forth since money isnt in abundance and even though im electrically inclined i dont want to have to fix anything!

What is everyones thoughts and experiences with these models?

I've had a klipsch 4.1 and the z5500. I preferred the z5500 for the control pod and inputs

Just get a digital amplifier/receiver and some good speakers for the fronts. Then use either HDMI or S/PDIF to connect it to your PC.

The reason i'm going with one of these system is to save some space, the z5500 seems to be the most cost efficent after doing some research on the klipsch and Gigaworks failure rates with the amps.

How about this one:
http://www.amazon.com/RCA-RT2911-10..._sbs_e_11?ie=UTF8&refRID=1XBJSMQQYCBJN60ZGJPN
It is a compact 5.1 receiver with HDMI as well as optical and coaxial S/PDIF. You'll definitely want the HDMI as it natively supports more than 2 channels (as opposed to S/PDIF that must use compression). The lag shouldn't be very much with low end receivers (counterintuitive and ironic!) as they don't do much in the way of processing.

Ended up picking up a europe spec model z5500 for $40 and a 500w step up converter for $40, what a deal and man does it sound hand over fist better than my x-530 LOL
thanks everyone for the inputs!