Building a squad for Rayquaza

The majority of raids depend on numbers. So if you have a dozen people show up, you're fine with anything decent. If 5 people show up, you'll need maxed out teams.

The easiest way to build up more useful ice now is to catch Spheal when it's rainy or snowing, and evolve to FB/Bliz Walrein at level 33-35. You have one Walrein, more would be good. Slightly higher DPS than Lapras (but less total damage), for massively less investment.

Golems are good against Ancient Power, or when it's partially cloudy out. Avoid Dragonite against Outrage (and to a lesser extent, Ancient Power), but it kicks butt against the air moves. Gardevoir is tanky, but very good when it's cloudy.

But in general, I'd build up more ice. Piloswine is also good, neutral to rock, not weak to it like most other Ice mon (or doubly weak for Articuno).

Jynx first it does the most damage so you want to make sure it can last as long as possible. everything else looks good.

Have you considered using one or multiple Mewtwo?

Your team is fine as is. No need to power anything up because with that team you can beat Rayquaza with just 2-3 other trainers.

I recommend putting Jynx in the #1 slot since she's got the highest DPS and is the most fragile to give her a better chance of firing off another Ice Punch or two before fainting and Gardevoir in the #6 slot because of her lack of a Super Effective fast move and her immunity tier resistance to Dragon moves.

Maybe use a fast TM on the Steel Wing/Dragon Pulse Dragonite. While Outrage is stronger, I wouldn't risk a charge TM because both Hyper Beam and Hurricane are worse against Rayquaza.

I'm building a squad also. Hadn't really focused on ice types before now...

I've got the following:

D-nite: Level 35.5/15ATK DT/O
D-nite: Level 34.5/15ATK DT/DP
D-nite: Level 34.5/12ATK DT/O
Piloswine: Level 30/14STK IS/AV
Lapras: Level 34/14ATK IS/B
Articuno: Level 30/13ATK FB/IB

Walrein: Three at Level 30 with FB/B (none have great IV's).

I also have four Level 20 Lapras and 3 Level 20 Cloysters, all with double ice. Raid parties can be anywhere from 5 to 20 people, depending on location/time of day. Do I need to spend the dust to power up a couple of the Lapras and/or Cloysters?