I'm not familiar with your layout, or why running speaker wire from your AVR? / receiver would be difficult on the left side of your TV any more than it would be for the right speaker.
With a $350 budget, there are many bookshelf speakers to choose from that would give you surprisingly good sound. With bookshelf speakers, you will need to add speaker stands, but they can be purchased for under $50/pair (leaving you around $300 for speaker, cabling and speaker wire).
What I'd do first is to go out and audition several different speakers (bookshelf or towers) to find the sound signature you like the best. One can also audition speakers in the home for 30 days via Internet-Direct companies (which is far the best way to audition speakers). Some companies to consider that would be around your price range (in order of price, not capability -- each have their fans):
$165 / pair (shipping extra) Philharmonic Audio Affordable Accuracy bookshelf speakers:
http://philharmonicaudio.com/ and
http://philharmonicaudio.com/aa.html (I have not auditioned these)
$225 / pair (includes shipping) EMP Tek R5Bi bookshelf speaker (formally E5Bi):
http://emptek.com/r5bi.php (I own these)
$219 - $249 / pair (? shipping) HTD Level TWO bookshelf speaker:
http://www.htd.com/Products/bookshelf-speakers/Level-TWO-Bookshelf-Speakers (I have not auditioned these)
$256 / pair (B-stock, ? shipping) NHT SuperOne 2.1 B:
http://www.nhthifi.com/Bookshelf-speaker-SuperOne-2-1_2 (I have not auditioned these)
$319 - $349 / pair (? shipping) HTD Level THREE bookshelf speaker:
http://www.htd.com/Products/level-three-speakers/Level-THREE-Bookshelf-Speakers (I have not auditioned these)
$318 / pair to $378 / pair ($50 shipping) Hsu HB-1 Mk2 bookshelf speaker:
http://www.hsuresearch.com/products/hb-1.html (I have auditioned these)
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Other speakers that may be worth a look:
$69 / pair (yeah, you heard me right -- free shipping) Sound Appeal SA-VF6.5S bookshelf speaker:
http://www.amazon.com/Premium-Bookshelf-Speakers-Sound-Appeal/dp/B00O17LP48 (just brought to my attention by zieglj01, and no, I have not auditioned these, but since you can get them on Amazon, it's a no brainer to try)
$141 / pair (free Amazon shipping) Sony SSCS5 bookshelf speaker:
http://www.amazon.com/Sony-SSCS5-3-Driver-Bookshelf-Speaker/dp/B00O8YLMVA (I have not auditioned these)