I will let others deal with your cabinet and ohm questions. Just saying the amp is plenty loud, even through an 8 ohm cab.
I have the Minimax, and for gigging it is a great little amp. Lots of tone options, variety of sounds depending what you want. Great features. But if you plan to use it for home practice, it is not a good choice. The fan is extremely loud. If I leave my practice room with the amp on, I can hear the fan all the way down the hall in another room. It will drive you nuts after a short while. As I said, at gigging volumes you will not notice the fan, but for home practice the fan is too loud. In all my years I have never heard another amp that has a fan that loud.
I have the Minimax, and for gigging it is a great little amp. Lots of tone options, variety of sounds depending what you want. Great features. But if you plan to use it for home practice, it is not a good choice. The fan is extremely loud. If I leave my practice room with the amp on, I can hear the fan all the way down the hall in another room. It will drive you nuts after a short while. As I said, at gigging volumes you will not notice the fan, but for home practice the fan is too loud. In all my years I have never heard another amp that has a fan that loud.