read some good things on this subject (for both downhill and xcountry) as a preseason exercise to add to your regiment
...anyone done so and can suggest any particular models?
I have a video with 'Radio Ron' who shows some of his off season training. This guy is in great shape. He does about an hour of stretching before he starts his workouts. He does use some type of rollerblade which could be considered ski skate (not sure as I never saw one before)
If you are a nordic skier roller skiing might be beneficial, but if not consider roller blading. Skating around Stanley Park is a hoot! If you are not a decent nordic skier, I wouldn't suggest trying to learn on roller skis. Concrete is hard stuff.
Roller blading (in-line skating) is much more accessible than roller skiing and provides good cross training for dh skiing. Both roller skiing and roller blading require lateral movement patterns and tipping the skate off centre that parallel dh ski movements. Both provide a good aerobic workout that is fun. However, roller skis are not as intuitive as roller blades, and requires decent basic nordic technique for turning (step turns) and controlling speed(pressuring the inside edges - so to speak). Using poles with roller skiing helps work out the upper body. Poles can be used with roller blades, but I have found it sort of awkward. Roller blades, on the other hand, are turned by tipping the edge to turn, and speed control is done by using a heel brake. With roller blades all you need are the blades and some protective gear, but with roller skis you will need nordic boots, poles, roller skis, and protective equipment.
If you look at this thread:
Inline skating at a competent intermediate level will help with the performance of every movement shown.
Just read your background info. Briko - Maplus makes good roller skis - if you want to do this, the next decision is classic v combi v skate skis. "Classic" roller skis typically have slower and softer wheels, and have a mechanism for reverse lock-up. You can also have speed reducers (a mechanism that places pressure on one wheel of each ski to slow momentum). Skae roller skiing, to me, seems more fun
Think about the surface you'll be on if you want to try roller skis. If you have smooth asphalt with no rough patches, smaller wheels have a better feel, but in lots of parts of the US something like
will be more user-friendly but more likely to roll your ankle.
It's a great exercise, but I agree that inline skates, or some of the specialty ski x-training skates that can be used with ski boots, have more transfer to alpine skiing. I also think that the skate model has much more transfer to skiing, though it can be a bit demanding if you haven't done Nordic skating before. Many shops will let you try before you buy.