Why would the IRS come after me? Using coinjoin has never been illegal. And the feds are starting to explicitly say its okay
https://cointelegraph.com/news/us-treasury-legitimate-use-crypto-mixerI know how to cj then send a couple more transactions to myself before sending to someone that might care. I've never heard of a service giving a shit for cj several hops removed from your transactions with them.
I've never used strike and I dont understand your last sentence. If you're asking where I buy Bitcoin the answer is Bisq.