Yakimiiis, do you use a tuner at all? If you don't, and the HTPC supplies all of your input signals, another solution is to just buy a power amp. Your HTPC will provide sufficient signal to drive a power amp directly and provide the input switching without needing the other features of a receiver or pre/pro. In essence, your HTPC is the pre/pro. That will require you use the analog outputs of the HTPC, but this should be adequate. I have an inexpensive computer sound card, and I'm satisfied with the sound quality using an inexpensive receiver for amplification and large bookshelf speakers. Interconnects are available that will adapt the 3.5mm jacks on the HTPC to phono inputs. I haven't shopped for 2-channel amps, so can't suggest a bunch of sources, but I do know that internet supplier Parts Express has several different ones to choose from starting at $160 for their Dayton APA150 with AudioSource 2-channel amps starting at $200. This will provide you with decent electronics at a price that will leave plenty left over to buy some nice speakers. Your HTPC will also provide adequate output drive for any powered sub, so if you decide to go 2.1 channel, just select a sub in your budget and hook it up to the HTPC with the same 3.5mm to phono plug interconnects.

In addition to the Internet speaker brands already mentioned, I'll add Ascend Acoustics. They also have good quality,modestly-priced speakers. I'm biased toward dual woofers, and Ascend is one of the few that has dual woofers in a non-tower speaker other than a center channel.

Bill