Skis: General rule of thumb for shaped ski length is to go anywhere from 10 to 20cm shorter than what you ski in a straight ski. A lot of that depends on the ski, your ability, skiing style, and terrain. Based on what you wrote, I'd guess your normally skiing something like a 200cm ski so going to something in the 180 range is probably about right. The trend in shaped skis seems to be falling on going towards the shorter size (e.g., just a bit shorter than your height).
Once you figure out what you like you can shop online for new skis. I just got my wife some new Volkl's from Al's Ski Barn in Maine (www.untracked.com). Area shops had them on sale for $399. Al's Ski Barn had them for $379 - no shipping, no tax. Ordered them on a Friday, got them the next Tuesday UPS ground. There's also Ebay or other auction sites for used gear. Alternatively, if you can hold out until Spring, you can catch end of season sales. If you can hold out until next fall, there should be more and more shaped skis available at ski swaps.
Bindings: Lots of different bindings out there with fancy terminology and features. All the new bindings out there do a decent job of releasing when their supposed to. Just make sure the DIN range (the numbers on the toe and heel piece for adjusting the spring and release point) is large enough to accommodate your weight and skiing style. Something in the range of 4 to 12 would probably work well for you. If you go with used equipment, make darned sure the bindings are not so old as to be obsolete. It doesn't take that many years for a binding to go from state-of-the-art to obsolete. When they hit that latter stage, no ski shop will work on them.
Boots: Unlike skis, I would not recommend going online for boots unless you know exactly what you want. Definitely don't go used. The liners of boots are designed to "pack out" and conform to the foot of the wearer. Used boots have taken the shape of their prior owner and may or may not "repack" to your shape. Besides, the liners absorb all the sweat from the prior owner. I'd hate to be the person using or buying one of my boots after I've worn them a season or two!
Size is key and boots are unquestionably the most important piece of equipment as you use your feet to steer your skis. The signals your feet send to your skis go through the boots first. A boot that's too loose will not send the steering input from your feet to your skis in a very efficient manner. Best bet is to find a decent boot fitter and work with them. Otto, a ski instructor at Liberty and DCSki columnist wrote a pretty darned good article on boot fitting that's somewhere in DCSki's archives. Probably would help to check that out.
Good luck.
