Here is my $0.02:
If you want a medium to stiff park ski with some all around go for Volkl Walls or AR6. Both have a medium waist (both 87 mm in the longer lengths I believe) and both have good edge hold and good pop, I'd even give the Wall a slight edge on the pop. Both have durable edges and will hold up well to a beating.
For a medium flex ski, your first choice, the Scratch FS, or Scratch Ghetto is a great choice and will do well for what you want. [shameless plug] I do have a pair of '08 Ghettos in 174 cm if you interested. PM me [/shameless plug] Many dislike Salomon, but I still think the Foil is a great choice here, and many are getting all excited about next year's Suspect (even though it is appears to be a Foil with maybe a slightly different core, a little built sidewall support and different graphics).
As for soft park skis, there are a ton of them - the all popular Invader is probably the best combination of price and performance (don't forget the Fujative in that catagory), but if you have the money to spend, you've got to include T-Halls.
scatch ghetto 174, or 181 if you like a longer ski --best ski out there