If you are going to spent time heli-skiing you might as well buy (or rent) your self a pair of wide powder skis. They will help you float above a lot of snow conditions that would be much tougher on a regular pair of slope skis. If you get a pair with a nice side cut and not to wide, they will still preform for you on the grommers as well.
Every member of a heli-skiing group should have an avalanche beacon / transceiver. As a rule, beacons should be worn whenever skiing out of bounds (off-piste). Beacons are the quickest way to find any member of a group caught and buried in an avalanche.
Beacons either continuously emit a specific frequency (457 MHz), or 'listen' to the same frequency emitted by other transceivers. When a member of a group is burred, all surviving members turn their beacons from 'transmit' mode to 'listen' mode, and either through audible changes in sound, or through a graphical display (depending on models) one is directed to the buried victim and beacon.
Be very familiar with this technology and practice before heading out into the back-country. Any operation worth spending time at will at a minimum, run through a practice session of finding a buried transceiver in the snow.
Beacons are expensive - though most heli-operations will provide a transceiver for use.
There is no point trying to find someone in an avalanche if you can't dig them out - and this is where a shovel is important. Generally every member of a skiing group should have one. Specially designed avalanche shovels are available from most well equipped back-country ski stores. These are designed to be light and folded into a size you can carry in small backpack without too much trouble.
If you can, try and get a shovel with a metal shovel blade. There are a number of shovels on the market made of plastic. While these might be light, they are not very effective (sometimes even useless) when trying to dig through avalanche debris. It's important to remember that all that nice fluffy light powder in an avalanche will jell into a concrete like substance after it all comes to a stop. Debris could well include rocks and ice chunks. If I was the one buried - I want want all those searching for me to have nice big steel shovels.
Another critical piece of avalanche rescue gear. Avalanche beacons (as described above) are good a for quickly finding the general area of a buried avalanche victim (to within a couple of square feet) though when time is precious, and the avalanche debris is starting to gel back together, it helps to know exactly where to dig. This is where a probe can tell you. The probe is a long collapsable pole (about ten feet long) that one can easily punch though the snow surface. By probing the suspected area, one can confirm the location of an avalanche victim.
This is an expensive piece of technology that has proven to save lives in avalanche situations. Basically, it's an airbag built into a back-pack. When the user is caught in an avalanche, by puling a handle on the pack-pack strap two large pouches infliate either side in a couple of seconds. These two inflatable pouches are enough to keep the user on the surface of most avalanche flows, so that when the avalanche does come to a stop, chances are the bag will at least be visible on the surface, making rescue much easier.
Each ABS system comes with a "trigger handle" that can easily be added and removed - as well as a safety strap to prevent unintentional triggering of the air bags. Some heli operators will not fly with ABS bags because of the potential risk of unintended inflation.