The headphone jack will IMO be your savior, I have lots of ways I execute this for my clients but long and short is you will not need an additional remote and the system/speakers will simply act as an extension of the TV, turn the volume up on the TV the volume of the attached speakers will behave accordingly greatly simplifying system use.
I am on my way out to complete an install for a client and will explain further this evening, but I would start looking for a small cheap digital amplifier with an auto 'on' / audio sensing power up (amazon, ebay & monoprice) $20-$50, and some passive speakers or a soundbar, you may actually already have a pair of speakers around the house that will work.
Also with the headphone Jack and as recommended above virtually any set of PC speakers will work.
The biggest issue you are most likely having is that your TV speakers are most likely rear facing off of the back of the TV and simply getting anything decent which faces out into the viewing area will resolve 90% of your issues.
Jay