As far as buying skis goes (for someone who doesn't ski a lot/didn't grow up skiing/isn't that strong for whatever reason), I'd say aim for the best middle ground. Relatively "soft" and forgiving, that has a little "rocker" in the tip of the ski to float in powder/absorb variable snow conditions, with some traditional camber underfoot that also allows you to bite into the snow and carve the ski. Maybe waist of the ski around 100mm, plenty wide enough for float in the powder but nothing crazy.
That being said, I would probably take the advice of the above posters. Go to a boot fitter, the BEST boot fitter, wherever you are. Ask random locals, they'll tell you who the best is. Get some good boots that fit you, but not too comfy cause you want them to perform. Don't let a salesman suck you in immediately with new liners, footbeds, etc.
Next, DEMO skis. It's hard to know what to buy if you don't know what you want. I ski over 100 days a year and spent quite a while last season trying out different skis before I figured out just what I wanted in that ski. Rent a demo ski. Ask the guys what they think the best all around demo ski is. Ask them what is the most popular ski. Try one out. if you don't like it, walk back in and try a different one. It doesn't cost anything to change the ski you're demoing.
Also, be sure and check the weather. If you know its gonna snow a bunch at night, or wake up and it has, go in and try out some wider skis. If its a sunny groomer day, try out something more suited to carving groomers. Good luck.