Yes mate. I do.
I am not connecting directly to an Arduino. I have another board it goes through.
If you post some of the choices available at your local shops we can offer some opinions.
Is that a secret or would you like to post a link to the information?
Do you understand whjat the "IMPEDANCE" of a speaker signifies? You could buy an impedance matching transformer. Youre keeping secrets from us and we cant give any useful help much as we would like to.
You are starting to sound like my wife 
. I have enough info for now. Don't worry about it mate.
Most helpers here assume that the only reason you came here is that because you have no idea what you are doing but that is not always true.
No worries mate. All good.