You are correct about the set having alot of doubles with different handles. It has alot of picks you really do not need. You already have all the picks you need with your southord set. Instead of spending the money on a massive ammount of lower quality picks, why not opt for a quality upgrade?
Check out
www.pererson-international.com they have great picks, expensive, but you get what you pay for. Also, check out some of our members here Locknewbie21 and Raimundo both offer handmade picks for sale, quantities are limited so you may have a bit of a wait, but it's well worth it. I own picks made by both men, it's rare when I use a pick not made by one of them.