ON3Ps are indeed really nice skis, but they do require a skier with some existing ability to really make the most of them. Also I'm sure you've noticed they are on the pricier end of the spectrum.
When you're starting out, a ski like an FR would be overkill. Instead I'd focus on getting a solid pair of well fitting boots, these are you most important piece of gear. As for skis, I wouldn't go looking to shell out too much, I'd go to your local shop and see what they have there for you to have a look at, see if you can get some demos, and speak to the guys in the shop, they should sort you out. A lot of beginner/entry level park skis are softer flexing, for you this shouldn't be a problem as you're pretty light.