As you've seen... the Factory does not offer reed-petals alone for your sled.
From the factory... the same polaris reed-block/reed-petal was used on a LOT of sleds.. from the 2005 900's through the PRO-RIDE RMK 800's and plenty of others.
Boysen replacement "SUPER STOCK" fiber reed-petals, Model # 570SF1 single stage OEM replacement reed-petals are the closest I've seen to stock
WPS part # 59-7570-1 $49.00/cylinder (you need TWO (2) kits per engine)
SPI also makes reed-petal replacements similar to OEM... WPS # 59-90126, $34.00/cylinder (you need TWO (2) kits per engine)
Reeds are something on a turbo sled you'd have to consider replacing at least every 1,000 miles or so, IMO.
Although there are Boysen "Carbon Tech" reed petals available for these sleds... I'm not sure how the engine would "digest" it if it were to break... cost is about $190.00 per set (enough to do both cylinders)