After reading through the entire post I think there's some great comments.
I would ask you the basic question "What makes you different"? After all, many consider racquet stringing somewhat of a commodity where people are focused primarily on cost and convenience.
For instance, you can be different by offering an initial consultation for every client (not customer) that will better match their playing level, style and racquet type to the right string and tension. We all know big box stores don't do that. You can also call the client a week after their stringing to see how their racquet is performing and ask for any referrals, offering $5 off their next stringing if their referral leads to a client. In short, be different and position yourself as their racquet consultant who also appreciates referrals!
Concerning the strings shown on your website, I would classify them as "Featured Strings". That helps the visitor to your website understand you offer an array of strings, but you are just highlighting the two.
Keep perfecting it... This site has great potential.
Head Prestige MP strung at 35 lbs with Cyclone 17. Still rocking my Klippermate.