Matt,
certainly it needs slightly drier culture before flowering, but damn - how it is fickle...
Last year it flowered in May - well, this year, and it is flowering right now again. Only 2 flowers manage to open, the rest 5 or 6 just withered away, have no clue why...it looks like a happy, healthy plant.
I'll keep my just the way it is, even thought your thinking about cacti is not bad, maybe you know what kind of cacti would be suitable, I guess not just anyone?