I can see Bitcoin hardfork to POS once the tech has been proven in Ethereum. Bitcoiners only care about the 21 millions hard cap and a secure network, not the exact consensus algorithm used.
You can just get it in majority of exchanges. In case your exchange doesn't support it (like me, Coinbase and Gemini, NYC, don't support Cardano), just use swapping service like changenow.io, so buy ETH from Coinbase and use changenow.io to swap it to ADA
I've been using changenow.io and it always works. As always, don't send in really large transaction, but one by one, maybe like 3000 ADA each time (this is what I do).
Yes I am a Cardano shiller.