Just skip the part about guaranteed BTCs, just call it the "$1m guaranteed". It's especially true for this particular tournament but I think you should stick with this policy for the rest of the tournaments also.
I'm not trying to be a smart-ass here, I'm just trying to help you out. Both players and you, the house, can get into alot of ugly spots and arguments if people start referring to these guaranteed BTC prizepools. Think about it.
We don't take it as being a smartass at all and we appreciate it. We want to have BTC in the title as well because that's what they will be receiving btc, therefore we are asking what your thoughts are regarding the best way to communicate this because it is a guaranteed prize pool of $1,000,000 paid out in btc.