You're over complicating it I think mate, unless you buying by the kilo or something lol
Just buy your BTC and send it. There is no such thing as being truly 100% anonymous on the internet especially not for sending money, but just because there is a transaction ID it doesn't mean people can easily see what you spent, where you spent it or what you bought. Think about it, if the sellers are safe to accept it then you are safe to send it, and you're sending it to the transaxe not directly to the seller too so... The potential security issue you have is while the bud is in transit, the better the stealth and the quicker the delivery the less chance of anything going wrong. Stealth of sending is where your main concern should be imo :)
Sorry if this didn't help!
Just buy your BTC and send it. There is no such thing as being truly 100% anonymous on the internet especially not for sending money, but just because there is a transaction ID it doesn't mean people can easily see what you spent, where you spent it or what you bought. Think about it, if the sellers are safe to accept it then you are safe to send it, and you're sending it to the transaxe not directly to the seller too so... The potential security issue you have is while the bud is in transit, the better the stealth and the quicker the delivery the less chance of anything going wrong. Stealth of sending is where your main concern should be imo :)
Sorry if this didn't help!