i completely agree with JDmay. for park, def don't get skis that dwarf you. i mean, i'm 178cm and i've got 169cm skis, so that may be a little too short, but i would rather have skis a bit short, than a bit long.
IF you plan on keepign these ski as you ge better, then ALWAYS choose big over small if you are having trouble making the deicision. SMaller will be easier to learn on. It'll be a little easier to spin and stuff, but once you learn, long skis will just give you more stability and you will feel much much better. I would get the long ones. Im 5'5 and I ride 177s. I dont think I would go any shorter.
if you want something to ride pretty easily...get foam core skis...they will suck if you ride them like over the 2nd year but are soft and forgiving...i personally like wood...but go for triplets or tweaks...if you're learning..get somewhat light to med. weight skis
that's easy: I won a freeride cross sponsored by Atomic and the first prize is a ski of my choice. I dont have any twins so I'm looking at getting the triplets.
The next question is though, do I get Triplet urbans or HP. Atomic told me the urbans are stiffer under the boot since it has 2 edges, the HP triplets are better for carving.
--------------------------------------
'Duran Duran bought Armada, Armada bought Microsoft, Microsoft bought MSP and AOL, AOL owns Time4 which owns the MountainSportsMedia which owns SKi, Skiing and RIP Freeze... so Armada now owns McDonalds and Coke.