Rick,
My suggestion is go for sound. The added cost is minimal, Bill sells the non-sound LM3 for $46, and the LM3S for $73. His prices are as good as you will find. So that equates to about 50% more, but you have sound. Speakers aren't expensive, iPhone speakers you can get for $1 to $1.50 each, so you aren't breaking the bank there. But ultimately, its a preference.
Chris