Entertainment Center: TVs, Stereos, VCRs and DVDs - Digital TV audio to in the wall home speakers

My old TV was analog and with my in wall speakers work great, I now have a LCD digital TV and want to hook my in the wall mounted speakers to it. I know it needs boosting and I have a surround sound system. The problem is that my surround sound system runs hot and has a built in fan for cooling and my home TV stays on almost 18 hours a day and I don't want something that runs hot to be boosting my sound signal for that many hours a day. Also I would like to get rid off the surround sound system and get something that is smaller that would do the amplifying for me. Also don't want to send a lot of money. I know it's a lot to ask for but I've ran out of ideas. Thanks for reading and any help would be greatly appreciated.

Any cheap stereo with an Aux input will do the job.