I have a 2020 277 SSX with the electric arch. I use the lower tow point in your photo for tubing. I use the tow point on the arch for pulling skiers. My white navigation light on the arch is also the ski pylon. Don’t pull a tube from the navigation light/tow pylon on the arch
I just did this with my 2020 277 SSX. The amp had to be replaced. I bought everything from the dealership (speakers, mounts and amp). The amp went from a JL Audio MV600/6i to a JL Audio MV800/8i. Basically a 6 channel amp to an 8 channel amp for the two extra speakers. I sold the removed amp on eBay and got back ⅓ the cost of the upgrade.