Replying to Ski length and mounting location questions.

Looking to get something new and right now I have my sights set on some 98 Kartels. Just a couple questions I need answered though. First I have never owned or used a rockered ski and therefore haven't the slightest clue on what size ski I should get (Information below). Second question is where should I mount the bindings. I already have some center mounted Abangs but I intend to use these new skis 70% in the park and 30% everywhere else which mostly includes short groomer runs and an occasional trip west. I Like the feeling of center mounted skis but given their width how far back would you recommend mounting them so they can be effective to some degree everywhere else (Deep powder days don't happen in MN so that's not a huge concern).

Information-
Height- 5'8"
Weight- 160
Skier type/style- I'm intermediate but want a ski that will last a while. I like to charge hard and I really enjoy hitting natural features. I also have a habit of being on my tails and noses a lot and therefore am looking for something with a medium flex. I'm not looking to do double corks.
Location- Central MN (Small hills)


Also if anyone has a binding recommendation with a higher DIN setting I would greatly appreciate it. (Budget would be up to about $300)

Thanks