The Ozone Access XC is a great kite for getting into depower. Choose the size depending on the area you're living/kiting and the winds you mostly have there.
The 6m covers a good and big wind range. From my point of view the 8m stop to be fun for beginners after 10kts, while the 6m is still good to handle, even in gusts and higher winds.
You'll also need a Harness for Depower Kiting. I prefer the Ozone XC Harness, it's like a rock climbing harness and doesn't slip all the way up to your chest.
Love my Frenzy FYX in 9m BUT I also have a Flow in 4m and a Yakuza on handles. Handlekites are more precise to control, which is sometimes an advantage when you're on an ATB. Depowers better to jump. It might be no mistake to purchase a 5m Flow or similar kite after the IMP, before making the step to (expensive) depower, as the IMP is really easy to handle and very forgiving.
Last but not least: ask a dealer near you for testing the kites you're interested in to buy next!!
Or even talk to helpful kitecrowd members here and meet them, I'm sure you can fly their's and get a better knowledge, if you friendly ask them.
Fly before you buy
Edit: LEI's are also great for Landboarding, but as you've mentioned the risk of braking them is always there, especially when you're a beginner this could become quite expensive. Using them on beaches is more safe than flying them on grassland.