I guess I could use the grommet kit, but where do the speakers go - on either side of the TV?
Yes. Some people here will disagree, but you could also place them atop the cabinet and not mess with the grommet kit. This would put the sound source below the image, but, in my experience, the mind quickly compensates, you get caught up in the show, and you never notice it.
I would recommend front facing ports like these ($345 shipped in Black):
http://www.htd.com/Products/bookshelf-speakers/Level-THREE-Bookshelf-Speakers?kpid=Level THREE Bookshelf Speakers 7-Series&gclid=Cj0KEQjwk7msBRCJj67khY2z_NIBEiQAPTFjv5STVSBUxB80efyBve2Ip1IUPK9JqxQJEt5dBpV8wEUaAgQ78P8HAQ
Note that wall mounts for these speakers are shown along the right hand side.
A receiver like this ($330 shipped - refurbished, but by Denon plus 3 year warranty!):
http://www.accessories4less.com/make-a-store/item/denavrx2100w/denon-avr-x2100w-7.2-receiver-wi-fi/bluetooth/airplay-w/3-yr-warranty/1.html
If refurbished gear is a concern, you can get the same unit new for $400:
http://www.amazon.com/Denon-AVR-X2100W-Bluetooth-Discontinued-Manufacturer/dp/B00KLC5YPS/ref=sr_1_4?ie=UTF8&qid=1435466698&sr=8-4&keywords=denon+receiver
Last, one or two subwoofers ($148 ea. shipped)
http://www.parts-express.com/dayton-audio-sub-1200-12-120-watt-powered-subwoofer--300-629
Total $923 with one sub and refurb receiver
up to $1151 for dual subs and new receiver
The sub is a ~17" cube. If you have floor space on both sides of the console, having two has benefits, but you can always add the second later, depending on how you feel the bass performs with just one. If ~17" cube is too large, you could back down to the SUB-1000 (~15" cube for $120) or SUB-800 (~13" cube for $100)
I should add that these are very inexpensive subs, but the designer made smart decisions - These subs commit sins of omission rather than sins of comission. What that means is they roll off around mid-30Hz (for the SUB-1200), so omit sounds below that frequency, but they don't add sounds that do not belong (sins of comission).
I have a $600 SVS 12" sub that goes deeper, but I prefer listening to the $148 sub because it is not so boomy in the bass!
Yamaha makes a good soundbar, but it won't come close to the performance of this system!